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

.gitea/workflows/release-nightly.yml

@@ -17,9 +17,9 @@ jobs:
       - uses: actions/checkout@v6
         with:
           fetch-depth: 0
-      - uses: actions/setup-go@v6
+      - uses: actions/setup-go@v5
         with:
-          go-version: stable
+          go-version-file: 'go.mod'
       - name: Build all platforms
         run: |
           VERSION=$(git describe --tags --always | sed 's/-/+/' | sed 's/^v//')
@@ -46,9 +46,9 @@ jobs:
           for f in gitea-mcp-extended_*.{tar.gz,zip}; do
             [ -f "$f" ] || continue
             # Delete old nightly file first (can't overwrite)
-            curl -sf -X DELETE --user "${{ gitea.actor }}:${{ secrets.GITHUB_TOKEN }}" \
+            curl -skf -X DELETE --user "${{ gitea.actor }}:${{ secrets.GITHUB_TOKEN }}" \
               "${{ gitea.server_url }}/api/packages/lethalbits/generic/gitea-mcp-extended/nightly/${f}" || true
-            curl -sf --user "${{ gitea.actor }}:${{ secrets.GITHUB_TOKEN }}" \
+            curl -skf --user "${{ gitea.actor }}:${{ secrets.GITHUB_TOKEN }}" \
               --upload-file "$f" \
               "${{ gitea.server_url }}/api/packages/lethalbits/generic/gitea-mcp-extended/nightly/${f}"
           done