Reduce Devcontainer docker layers (home-assistant#157412)

Author: edenhaus

Dockerfile.dev

@@ -35,25 +35,22 @@ COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv
 
 USER vscode
 
-COPY .python-version ./
-RUN uv python install
-
 ENV VIRTUAL_ENV="/home/vscode/.local/ha-venv"
-RUN uv venv $VIRTUAL_ENV
+RUN --mount=type=bind,source=.python-version,target=.python-version \
+    uv python install \
+    && uv venv $VIRTUAL_ENV
 ENV PATH="$VIRTUAL_ENV/bin:$PATH"
 
-WORKDIR /tmp
-
 # Setup hass-release
 RUN git clone --depth 1 https://github.com/home-assistant/hass-release ~/hass-release \
     && uv pip install -e ~/hass-release/
 
 # Install Python dependencies from requirements
-COPY requirements.txt ./
-COPY homeassistant/package_constraints.txt homeassistant/package_constraints.txt
-RUN uv pip install -r requirements.txt
-COPY requirements_test.txt requirements_test_pre_commit.txt ./
-RUN uv pip install -r requirements_test.txt
+RUN --mount=type=bind,source=requirements.txt,target=requirements.txt \
+    --mount=type=bind,source=homeassistant/package_constraints.txt,target=homeassistant/package_constraints.txt \
+    --mount=type=bind,source=requirements_test.txt,target=requirements_test.txt \
+    --mount=type=bind,source=requirements_test_pre_commit.txt,target=requirements_test_pre_commit.txt \
+    uv pip install -r requirements.txt -r requirements_test.txt
 
 WORKDIR /workspaces