fix: update Docker registry credentials to use Gitea secrets

.gitea/workflows/build.yaml

@@ -66,8 +66,8 @@ jobs:
         uses: docker/login-action@v2
         with:
           registry: git.ryankegel.com:3000
-          username: ryan #${{ secrets.REGISTRY_USERNAME }} # Stored as a Gitea secret
-          password: 0x013h #${{ secrets.REGISTRY_TOKEN }} # Stored as a Gitea secret (use a PAT here)
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}
 
       - name: Push Backend Image to Gitea Registry
         run: |