go.mod: don't enforce latest go version

Commit e9d8229 updated the version of go to
use for this module, but also updated the go directive in go.mod, preventing
users of this module to use lower versions.

For modules used as library, Go generally recommends supporting at least the
current stable and "oldstable" (stable -1) releases.

This patch:

- downgrades the go directive in go.mod to go1.25
- updates github actions workflows to test both the specified version (1.26)
  and the version specified in go.mod (minimal version).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

.github/workflows/check.yml

@@ -10,20 +10,23 @@ jobs:
   # Linter checker
   #
   linters:
-    name: Linters
+    name: Linters (${{ matrix.go-version || 'minimum' }})
     runs-on: ubuntu-22.04
     timeout-minutes: 10
 
     strategy:
       matrix:
-        go-version: [1.26]
-
+        go-version:
+          - "" # empty; fall back on go-version-file (use go.mod); see https://github.com/actions/setup-go/issues/450#issuecomment-3620402646
+          - 1.26
     steps:
-      - uses: actions/setup-go@v6
+      - uses: actions/checkout@v6
+      - name: install Go
+        uses: actions/setup-go@v6
         with:
           go-version: ${{ matrix.go-version }}
-
-      - uses: actions/checkout@v6
+          go-version-file: "go.mod" # used when go-version is not specified.
+          check-latest: true
       - uses: golangci/golangci-lint-action@v9
         with:
           version: v2.9

.github/workflows/ci-unit-test.yml

@@ -9,10 +9,14 @@ on:
 
 jobs:
   unit-test:
-    name: Unit Test
+    name: Unit Test (${{ matrix.go-version || 'minimum' }})
     runs-on: ubuntu-22.04
     timeout-minutes: 10
-
+    strategy:
+      matrix:
+        go-version:
+          - "" # empty; fall back on go-version-file (use go.mod); see https://github.com/actions/setup-go/issues/450#issuecomment-3620402646
+          - 1.26
     steps:
       - uses: actions/checkout@v6
         with:
@@ -22,7 +26,9 @@ jobs:
       - name: install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26'
+          go-version: ${{ matrix.go-version }}
+          go-version-file: "go.mod" # used when go-version is not specified.
+          check-latest: true
 
       - name: set env
         shell: bash

.github/workflows/ci-userspace-convertor.yml

@@ -14,9 +14,14 @@ on:
 
 jobs:
   run-ci-userspace-convertor:
-    name: Run CI | Userspace Convertor
+    name: Run CI | Userspace Convertor (${{ matrix.go-version || 'minimum' }})
     runs-on: ubuntu-22.04
     timeout-minutes: 10
+    strategy:
+      matrix:
+        go-version:
+          - "" # empty; fall back on go-version-file (use go.mod); see https://github.com/actions/setup-go/issues/450#issuecomment-3620402646
+          - 1.26
     container:
       image: ghcr.io/${{ inputs.github-repository }}/overlaybd-ci-images:${{ inputs.image-tag }}
       credentials:
@@ -85,7 +90,9 @@ jobs:
       - name: install Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.26'
+          go-version: ${{ matrix.go-version }}
+          go-version-file: "go.mod" # used when go-version is not specified.
+          check-latest: true
 
       - name: set env
         shell: bash

.github/workflows/codeql.yml

@@ -25,6 +25,7 @@ jobs:
     - uses: actions/setup-go@v6
       with:
         go-version: '1.26'
+        check-latest: true
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL

go.mod

@@ -1,6 +1,11 @@
 module github.com/containerd/accelerated-container-image
 
-go 1.26.0
+// The go directive declares the minimum Go version required for this module.
+//
+// DO NOT change this version unless support for older Go versions is dropped
+// or the module requires newer Go features. To update the version used for CI
+// and releases, update "go-version" and "GO_VERSION" in "/.github/workflows".
+go 1.25
 
 require (
 	github.com/containerd/containerd/api v1.8.0