Add signature for tag releases, upload to gitea releases itself (#116)

GPG signature keys are not set yet.

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/116
Reviewed-by: Jason Song <i@wolfogre.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-committed-by: Lunny Xiao <xiaolunwen@gmail.com>

.gitea/workflows/release-tag.yml

@@ -16,6 +16,12 @@ jobs:
       - uses: actions/setup-go@v3
         with:
           go-version: '>=1.20.1'
+      - name: Import GPG key
+        id: import_gpg
+        uses: crazy-max/ghaction-import-gpg@v5
+        with:
+          gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
+          passphrase: ${{ secrets.PASSPHRASE }}
       - name: goreleaser
         uses: https://github.com/goreleaser/goreleaser-action@v4
         with:
@@ -29,3 +35,6 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           S3_REGION: ${{ secrets.AWS_REGION }}
           S3_BUCKET: ${{ secrets.AWS_BUCKET }}
+          GORELEASER_FORCE_TOKEN: 'gitea'
+          GITEA_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GPG_FINGERPRINT: ${{ steps.import_gpg.outputs.fingerprint }}