[github-action] release - Empty allowedSignersFile

Update the release Github Action workflow to create an empty allowedSignersFile
and configure git to use it. This prevents failures when tags are signed
with an SSH based key. Without this configuration, `git tag -v` errors
with:

```
Output: error: gpg.ssh.allowedSignersFile needs to be configured and exist for ssh signature verification
```

Signed-off-by: Jared Ledvina <jared.ledvina@datadoghq.com>

.github/workflows/release.yml

@@ -36,6 +36,9 @@ jobs:
 
       - name: Check signature
         run: |
+          # git tag -v requires an allowedSignersFile to be configured and exist for ssh signature verification
+          touch ${{ runner.temp }}/empty-allowedSignersFile
+          git config --global gpg.ssh.allowedSignersFile ${{ runner.temp }}/empty-allowedSignersFile
           releasever=${{ github.ref }}
           releasever="${releasever#refs/tags/}"
           TAGCHECK=$(git tag -v ${releasever} 2>&1 >/dev/null) ||