lint: switch to uv for python management in linter

https://docs.astral.sh/uv/

Install python in the linter using uv and a venv.
This is faster and more simple than building pyenv.

ci/lint/01_install.sh

@@ -22,25 +22,14 @@ ${CI_RETRY_EXE} apt-get update
 # - moreutils (used by scripted-diff)
 ${CI_RETRY_EXE} apt-get install -y cargo curl xz-utils git gpg moreutils
 
-PYTHON_PATH="/python_build"
-if [ ! -d "${PYTHON_PATH}/bin" ]; then
-  (
-    ${CI_RETRY_EXE} git clone --depth=1 https://github.com/pyenv/pyenv.git
-    cd pyenv/plugins/python-build || exit 1
-    ./install.sh
-  )
-  # For dependencies see https://github.com/pyenv/pyenv/wiki#suggested-build-environment
-  ${CI_RETRY_EXE} apt-get install -y build-essential libssl-dev zlib1g-dev \
-    libbz2-dev libreadline-dev libsqlite3-dev curl llvm \
-    libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev \
-    clang
-  env CC=clang python-build "$(cat "/.python-version")" "${PYTHON_PATH}"
-fi
-export PATH="${PYTHON_PATH}/bin:${PATH}"
+# Install Python and create venv using uv (reads version from .python-version)
+uv venv /python_env
+
+export PATH="/python_env/bin:${PATH}"
 command -v python3
 python3 --version
 
-${CI_RETRY_EXE} pip3 install \
+uv pip install --python /python_env \
   lief==0.17.5 \
   mypy==1.19.1 \
   pyzmq==27.1.0 \

ci/lint/06_script.sh

@@ -12,7 +12,7 @@ set -o errexit -o pipefail -o xtrace
 # of the mounted bitcoin src dir.
 git config --global --add safe.directory /bitcoin
 
-export PATH="/python_build/bin:${PATH}"
+export PATH="/python_env/bin:${PATH}"
 
 if [ -n "${LINT_CI_IS_PR}" ]; then
   export COMMIT_RANGE="HEAD~..HEAD"

ci/lint_imagefile

@@ -6,6 +6,10 @@
 
 FROM mirror.gcr.io/ubuntu:24.04
 
+# Pin uv to minor version to avoid breaking changes:
+# https://docs.astral.sh/uv/reference/policies/versioning/
+COPY --from=ghcr.io/astral-sh/uv:0.10 /uv /uvx /bin/
+
 COPY ./ci/retry/retry /ci_retry
 COPY ./.python-version /.python-version
 COPY ./ci/lint/01_install.sh /install.sh