CI: Bump release to Go 1.23

Author: decke

.github/workflows/release.yaml

@@ -29,6 +29,6 @@ jobs:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         goos: ${{ matrix.goos }}
         goarch: ${{ matrix.goarch }}
-        goversion: "1.22"
+        goversion: "1.23"
         extra_files: LICENSE README.md smtprelay.ini
         ldflags: -s -w -X "main.appVersion=${{ env.APP_VERSION }}" -X "main.buildTime=${{ env.BUILD_TIME }}"