fix gitea backend: install uv via shell, not setup-uv action

astral-sh/setup-uv composite action makes internal API calls
that Gitea resolves against localhost, failing because astral-sh
isn't a local user. Use the official install script instead:
  curl -LsSf https://astral.sh/uv/install.sh | sh

.gitea/workflows/ci.yml

@@ -16,9 +16,9 @@ jobs:
         uses: https://github.com/actions/checkout@v4
 
       - name: Set up uv
-        uses: https://github.com/astral-sh/setup-uv@v4
-        with:
-          version: latest
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+        env:
+          UV_INSTALL_DIR: /usr/local/bin
 
       - name: Install dependencies
         run: uv sync --dev

.gitea/workflows/deploy.yml

@@ -127,9 +127,9 @@ jobs:
         uses: https://github.com/actions/checkout@v4
 
       - name: Set up uv
-        uses: https://github.com/astral-sh/setup-uv@v4
-        with:
-          version: latest
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+        env:
+          UV_INSTALL_DIR: /usr/local/bin
 
       - name: Download scan results
         uses: https://github.com/actions/download-artifact@v4

.gitea/workflows/harden.yml

@@ -127,9 +127,9 @@ jobs:
         uses: https://github.com/actions/checkout@v4
 
       - name: Set up uv
-        uses: https://github.com/astral-sh/setup-uv@v4
-        with:
-          version: latest
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+        env:
+          UV_INSTALL_DIR: /usr/local/bin
 
       - name: Download scan results
         uses: https://github.com/actions/download-artifact@v4

.gitea/workflows/rebuild-all.yml

@@ -126,9 +126,9 @@ jobs:
         uses: https://github.com/actions/checkout@v4
 
       - name: Set up uv
-        uses: https://github.com/astral-sh/setup-uv@v4
-        with:
-          version: latest
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+        env:
+          UV_INSTALL_DIR: /usr/local/bin
 
       - name: Download scan results
         uses: https://github.com/actions/download-artifact@v4

.gitea/workflows/release.yml

@@ -15,9 +15,9 @@ jobs:
         uses: https://github.com/actions/checkout@v4
 
       - name: Set up uv
-        uses: https://github.com/astral-sh/setup-uv@v4
-        with:
-          version: latest
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+        env:
+          UV_INSTALL_DIR: /usr/local/bin
 
       - name: Build package
         run: uv build --out-dir dist/

dev/scripts/backends/gitea.py

@@ -32,11 +32,14 @@ def _setup_buildx_step() -> str:
 
 
 def _setup_uv_step(uv_version: str) -> str:
-    return f"""\
+    # astral-sh/setup-uv is a composite action that calls the Gitea API
+    # internally, which fails because 'astral-sh' isn't a local user.
+    # Install uv directly via the official installer script instead.
+    return """\
       - name: Set up uv
-        uses: https://github.com/astral-sh/setup-uv@v4
-        with:
-          version: {uv_version}"""
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+        env:
+          UV_INSTALL_DIR: /usr/local/bin"""
 
 
 def _build_push_step(