ci(workflows): update Go version configuration to use oldstable

Author: k1LoW

.github/workflows/ci.yml

@@ -24,13 +24,13 @@ jobs:
         id: setup-go
         uses: actions/setup-go@4b73464bb391d4059bd26b0524d20df3927bd417 # v6.3.0
         with:
-          go-version-file: go.mod
+          go-version: oldstable
 
       - name: Run lint
         uses: reviewdog/action-golangci-lint@f9bba13753278f6a73b27a56a3ffb1bfda90ed71 # v2.8.0
         with:
           fail_level: warning
-          go_version_file: go.mod
+          go_version: oldstable
 
       - name: Run gostyle
         uses: k1LoW/gostyle-action@e1b847d37b3041c5fdb8b911bcf00b350779ca61 # v1.5.1

.github/workflows/tagpr.yml

@@ -16,7 +16,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@4b73464bb391d4059bd26b0524d20df3927bd417 # v6.3.0
         with:
-          go-version-file: go.mod
+          go-version: oldstable
 
       - id: run-tagpr
         name: Run tagpr