do not require git for linting

While it is reasonable for local executions to exempt files not under
version-ctrl from linting, this is not actually helpful for pipelines.
Guard against absence of git and thus remove the necessity for pipelines
to install git.

.ci/lint-flake8

@@ -8,11 +8,15 @@ src_dir="${1:-"$(readlink -f "$(dirname "${0}")/..")"}"
 error=0
 
 # ignore files that are not under version-ctrl (helpful for local runs)
-GIT_DIR="${src_dir}/.git" \
-GIT_WORKTREE="${src_dir}" \
-    untracked=$(git status --porcelain=v2 | grep -e '^? ' | sed 's/^? //g')
+if which git &>/dev/null; then
+    GIT_DIR="${src_dir}/.git" \
+    GIT_WORKTREE="${src_dir}" \
+        untracked=$(git status --porcelain=v2 | grep -e '^? ' | sed 's/^? //g')
 
-exclude_args=$(echo -n "${untracked}" | tr \\n ,)
+    exclude_args=$(echo -n "${untracked}" | tr \\n ,)
+else
+    exclude_args=""
+fi
 
 # flake8 / the linter it instruments cannot handle our special type-hints (CliHint)
 if flake8 \

.github/workflows/build-and-test.yaml

@@ -364,9 +364,6 @@ jobs:
     container:
       image: python:3.12-alpine
     steps:
-    - name: install git
-      run: |
-        apk add --no-cache git
     - uses: actions/checkout@v4
     - name: Retrieve Distribution Packages
       uses: actions/download-artifact@v4