Add prefix to use ghaction-import-gpg (#120)

See https://gitea.com/gitea/act_runner/actions/runs/254

Related to #116

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/120
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Jason Song <i@wolfogre.com>
Co-committed-by: Jason Song <i@wolfogre.com>

.gitea/workflows/release-tag.yml

@@ -18,7 +18,7 @@ jobs:
           go-version: '>=1.20.1'
       - name: Import GPG key
         id: import_gpg
-        uses: crazy-max/ghaction-import-gpg@v5
+        uses: https://github.com/crazy-max/ghaction-import-gpg@v5
         with:
           gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
           passphrase: ${{ secrets.PASSPHRASE }}