Preview upcoming Windows VS 2026 + macOS 26 runner images

GitHub is migrating three runner labels in the next ~4 weeks:

- `windows-latest` and `windows-2025` get Visual Studio 2026
  between June 8-15, 2026, replacing the VS 2022 toolchain.
- `macos-latest` starts pointing to macOS 26 over a 30-day
  rollout beginning June 15, 2026.

To shake out incompatibilities ahead of the brownout, retarget
every affected `runs-on` value across `ci`, `codeql`, and
`release` workflows to the temporary `windows-2025-vs2026`
preview label and the `macos-26` label (GA since
February 2026). The two `matrix.os == 'windows-latest'`
archive-packaging conditionals in `release.yml` are updated to
compare against the renamed matrix value so the Windows-vs-Unix
branch selection still works.

Also swap `macos-15-intel` to `macos-26-intel` for the
`x86_64-apple-darwin` release target. Both became GA in the same
February 2026 announcement; doing one without the other is an
asymmetry not worth keeping in a "preview the freshest images"
branch.

The `codeql` swift conditional is updated for completeness even
though swift is not in the active language matrix.

This change is for fork-local CI validation only and should not
be merged upstream.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: EliahKagan

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
     strategy:
       matrix:
         os:
-          - windows-2025
+          - windows-2025-vs2026
           - ubuntu-latest
 
     runs-on: ${{ matrix.os }}
@@ -259,9 +259,9 @@ jobs:
     strategy:
       matrix:
         os:
-          - windows-latest
+          - windows-2025-vs2026
           - windows-11-arm
-          - macos-latest
+          - macos-26
           - ubuntu-latest
           - ubuntu-24.04-arm
         include:
@@ -331,7 +331,7 @@ jobs:
     strategy:
       matrix:
         os:
-          - windows-latest
+          - windows-2025-vs2026
           - windows-11-arm
         include:
           - test-args: ""
@@ -450,7 +450,7 @@ jobs:
         run: cargo nextest run --workspace --no-fail-fast --exclude gix-error
 
   test-32bit-windows-size-doc:
-    runs-on: windows-latest
+    runs-on: windows-2025-vs2026
 
     env:
       TARGET: i686-pc-windows-msvc

.github/workflows/codeql.yml

@@ -34,7 +34,7 @@ jobs:
     #   - https://gh.io/supported-runners-and-hardware-resources
     #   - https://gh.io/using-larger-runners (GitHub.com only)
     # Consider using larger runners or machines with greater resources for possible analysis time improvements.
-    runs-on: ${{ (matrix.language == 'swift' && 'macos-latest') || 'ubuntu-latest' }}
+    runs-on: ${{ (matrix.language == 'swift' && 'macos-26') || 'ubuntu-latest' }}
     permissions:
       # required for all workflows
       security-events: write  # Required for uploading SARIF to view in the Security tab.

.github/workflows/release.yml

@@ -134,18 +134,18 @@ jobs:
           - target: s390x-unknown-linux-gnu
             os: ubuntu-latest
           - target: x86_64-apple-darwin
-            os: macos-15-intel
+            os: macos-26-intel
           - target: aarch64-apple-darwin
-            os: macos-latest
+            os: macos-26
           - target: x86_64-pc-windows-msvc
-            os: windows-latest
+            os: windows-2025-vs2026
           - target: x86_64-pc-windows-gnu
-            os: windows-latest
+            os: windows-2025-vs2026
             rust: stable-x86_64-gnu
           - target: i686-pc-windows-msvc
-            os: windows-latest
+            os: windows-2025-vs2026
           - target: aarch64-pc-windows-msvc
-            os: windows-latest
+            os: windows-2025-vs2026
         # On linux we build with musl which causes trouble with open-ssl. For now, just build max-pure there.
         # It's a TODO. See https://github.com/GitoxideLabs/gitoxide/issues/1242.
         exclude:
@@ -280,7 +280,7 @@ jobs:
           cp -- {README.md,LICENSE-*,CHANGELOG.md} "$ARCHIVE/"
 
       - name: Build archive (Windows)
-        if: matrix.os == 'windows-latest'
+        if: matrix.os == 'windows-2025-vs2026'
         run: |
           file -- "$TARGET_DIR/$PROFILE"/{ein,gix}.exe
           cp -- "$TARGET_DIR/$PROFILE"/{ein,gix}.exe "$ARCHIVE/"
@@ -290,7 +290,7 @@ jobs:
           echo "ASSET_SUM=$ARCHIVE.zip.sha256" >> "$GITHUB_ENV"
 
       - name: Build archive (Unix)
-        if: matrix.os != 'windows-latest'
+        if: matrix.os != 'windows-2025-vs2026'
         run: |
           file -- "$TARGET_DIR/$PROFILE"/{ein,gix}
           cp -- "$TARGET_DIR/$PROFILE"/{ein,gix} "$ARCHIVE/"
@@ -306,7 +306,7 @@ jobs:
 
   # Add a macOS universal binary archive for a feature using its built aarch64 and x86_64 assets.
   build-macos-universal2-release:
-    runs-on: macos-latest
+    runs-on: macos-26
 
     needs: [ create-release, build-release ]
 
@@ -523,19 +523,19 @@ jobs:
         build: [ win-msvc, win-gnu, win32-msvc, win32-gnu ]
         include:
           - build: win-msvc
-            os: windows-latest
+            os: windows-2025-vs2026
             rust: stable
             target: x86_64-pc-windows-msvc
           - build: win-gnu
-            os: windows-latest
+            os: windows-2025-vs2026
             rust: stable-x86_64-gnu
             target: x86_64-pc-windows-gnu
           - build: win32-msvc
-            os: windows-latest
+            os: windows-2025-vs2026
             rust: stable
             target: i686-pc-windows-msvc
           - build: win32-gnu
-            os: windows-latest
+            os: windows-2025-vs2026
             rust: stable
             target: i686-pc-windows-gnu