fix(ci): restore build dependency fallback and add --group ci to uv sync

- Add --group ci to uv sync in semantic-release.yml so the build package
  (in [dependency-groups].ci) is installed before PSR runs
- Restore self-healing fallback in build.sh: if build is not found,
  install it via uv pip or pip rather than hard-failing
- Keep --no-isolation on python -m build to avoid broken .venv/bin/pip
  stub in uv-managed venvs

The original build.sh had a self-healing fallback that worked at v1.5.2.
PR #197 added uv sync --all-extras (correct, needed for sdk-go-export-spec)
but --all-extras does not install [dependency-groups]. PR #198 removed the
fallback assuming --all-extras covered build — it does not.

Author: fgogolli

.github/workflows/semantic-release.yml

@@ -102,7 +102,7 @@ jobs:
         uses: astral-sh/setup-uv@v7
 
       - name: Install ORB
-        run: uv sync --all-extras
+        run: uv sync --all-extras --group ci
 
       - name: Python Semantic Release
         id: release

dev-tools/package/build.sh

@@ -34,8 +34,14 @@ if [ "$QUIET" = false ]; then
     echo "INFO: Checking build dependencies..."
 fi
 if ! $RUN_TOOL python -c "import build" 2>/dev/null; then
-    echo "ERROR: 'build' package not found. Ensure 'uv sync --all-extras' has been run." >&2
-    exit 1
+    if [ "$QUIET" = false ]; then
+        echo "INFO: Installing build dependencies..."
+    fi
+    if command -v uv >/dev/null 2>&1; then
+        uv pip install build --quiet
+    else
+        $RUN_TOOL pip install build
+    fi
 fi
 
 # Build package