ci: bump actions/upload-artifact from v5 (and one v4) to v7

All of our `actions/upload-artifact` uses are still on v5, with one
stray v4 occurrence. Keeping them on these versions would leave the
artifact-upload steps running on Node.js 20, which GitHub is phasing
out, and would eventually cause all upload steps to fail.

Going from v5 directly to v7 folds in two release bumps:

- v6 switches the action's default runtime from Node.js 20 to
  Node.js 24 (v5 had preliminary Node 24 support but still defaulted
  to Node 20). This is the main motivation for bumping now: it gets
  us off the deprecated runtime.
- v7 adds two opt-in features: direct (unzipped) single-file uploads
  via a new `archive: false` parameter, and an internal conversion of
  the action to ESM to match the updated `@actions/*` packages.

Risk analysis: we never pass `archive`, so the zip-as-usual behavior
is unchanged. We also do not `require('@actions/*')` from any calling
workflow, so the ESM migration cannot affect us. The upload steps we
care about -- tracked files/build artifacts and failing-test
directories -- keep the same inputs (`name`, `path`) and outputs, so
the diff is purely the `@vN` identifier. The main precondition is a
recent Actions Runner (>= 2.327.1), which the github.com-hosted
runners used by our CI already satisfy.

While at it, align the one remaining `@v4` occurrence with the rest
so that every `upload-artifact` step uses the same version.

See also:

- Release notes: https://github.com/actions/upload-artifact/releases
- Compare: actions/upload-artifact@v5...v7

Originally-authored-by: dependabot[bot] <support@github.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

.github/workflows/main.yml

@@ -123,7 +123,7 @@ jobs:
     - name: zip up tracked files
       run: git archive -o artifacts/tracked.tar.gz HEAD
     - name: upload tracked files and build artifacts
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: windows-artifacts
         path: artifacts
@@ -157,7 +157,7 @@ jobs:
       run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: failed-tests-windows-${{ matrix.nr }}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -208,7 +208,7 @@ jobs:
     - name: zip up tracked files
       run: git archive -o artifacts/tracked.tar.gz HEAD
     - name: upload tracked files and build artifacts
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: vs-artifacts
         path: artifacts
@@ -244,7 +244,7 @@ jobs:
       run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: failed-tests-windows-vs-${{ matrix.nr }}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -270,7 +270,7 @@ jobs:
       shell: pwsh
       run: meson compile -C build
     - name: Upload build artifacts
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: windows-meson-artifacts
         path: build
@@ -305,7 +305,7 @@ jobs:
       run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v7
       with:
         name: failed-tests-windows-meson-${{ matrix.nr }}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -349,7 +349,7 @@ jobs:
       run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: failed-tests-${{matrix.vector.jobname}}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -449,7 +449,7 @@ jobs:
       run: sudo --preserve-env --set-home --user=builder ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v7
       with:
         name: failed-tests-${{matrix.vector.jobname}}
         path: ${{env.FAILED_TEST_ARTIFACTS}}