fix(ci): use compatible action versions for Forgejo runner

- Downgrade actions/setup-go from v6 to v5 (node24 not supported)
- Downgrade goreleaser-action from v6 to v5
- Add CI workflow with goreleaser snapshot on push to main
- Add .goreleaser.yaml configuration

.github/workflows/release.yaml

@@ -14,9 +14,9 @@ jobs:
         with:
           fetch-depth: 0
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@v5
         with:
-          go-version: ">=1.25.1"
+          go-version-file: go.mod
       - name: Test code
         run: make test
       - name: Import GPG key
@@ -26,7 +26,7 @@ jobs:
           gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
           passphrase: ${{ secrets.GPG_PASSPHRASE }}
       - name: Run GoReleaser
-        uses: https://github.com/goreleaser/goreleaser-action@v6
+        uses: https://github.com/goreleaser/goreleaser-action@v5
         env:
           GITEA_TOKEN: ${{ secrets.PACKAGES_TOKEN }}
           GPG_FINGERPRINT: ${{ steps.import_gpg.outputs.fingerprint }}