fix: resolve CI failures in release workflows

- Downgrade setup-go@v6 to v5 (v6 breaks with "version: not found" on Gitea runner)
- Use go-version-file instead of go-version: stable for consistency
- Add skip_tls_verify to goreleaser gitea_urls for Cloudflare origin cert
- Add curl -k flag for package registry uploads

.goreleaser.yaml

@@ -73,4 +73,5 @@ release:
 gitea_urls:
   api: https://git.lethalbits.com/api/v1
   download: https://git.lethalbits.com
+  skip_tls_verify: true
 force_token: gitea