GH-43883: [CI] Remove Python version guard when installing GCS testbench

.github/workflows/cpp.yml

@@ -472,7 +472,7 @@ jobs:
         shell: msys2 {0}
         env:
           PIPX_BIN_DIR: /usr/local/bin
-          PIPX_PYTHON: ${{ steps.python-install.outputs.python-path }}
+          PIPX_BASE_PYTHON: ${{ steps.python-install.outputs.python-path }}
         run: |
           ci/scripts/install_gcs_testbench.sh default
       - name: Test

ci/docker/conda-cpp.dockerfile

@@ -44,7 +44,7 @@ RUN mamba install -q -y \
 
 # We want to install the GCS testbench using the Conda base environment's Python,
 # because the test environment's Python may later change.
-ENV PIPX_PYTHON=/opt/conda/bin/python3
+ENV PIPX_BASE_PYTHON=/opt/conda/bin/python3
 COPY ci/scripts/install_gcs_testbench.sh /arrow/ci/scripts
 RUN /arrow/ci/scripts/install_gcs_testbench.sh default
 

ci/docker/python-wheel-manylinux-test.dockerfile

@@ -19,13 +19,19 @@ ARG arch
 ARG python_image_tag
 FROM ${arch}/python:${python_image_tag}
 
-# RUN pip install --upgrade pip
-
 # pandas doesn't provide wheel for aarch64 yet, so cache the compiled
 # test dependencies in a docker image
 COPY python/requirements-wheel-test.txt /arrow/python/
 RUN pip install -r /arrow/python/requirements-wheel-test.txt
 
+# Install the GCS testbench with the system Python
+RUN apt-get update -y -q && \
+    apt-get install -y -q \
+        build-essential \
+        python3-dev && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists*
+
 COPY ci/scripts/install_gcs_testbench.sh /arrow/ci/scripts/
-ARG python
-RUN PYTHON_VERSION=${python} /arrow/ci/scripts/install_gcs_testbench.sh default
+ENV PIPX_PYTHON=/usr/bin/python3 PIPX_PIP_ARGS=--prefer-binary
+RUN /arrow/ci/scripts/install_gcs_testbench.sh default

ci/scripts/install_gcs_testbench.sh

@@ -39,18 +39,21 @@ if [[ "${version}" -eq "default" ]]; then
   version="v0.39.0"
 fi
 
-: ${PIPX_PYTHON:=$(which python3)}
+# The Python to install pipx with
+: ${PIPX_BASE_PYTHON:=$(which python3)}
+# The Python to install the GCS testbench with
+: ${PIPX_PYTHON:=${PIPX_BASE_PYTHON:-$(which python3)}}
 
 export PIP_BREAK_SYSTEM_PACKAGES=1
-${PIPX_PYTHON} -m pip install -U pipx
+${PIPX_BASE_PYTHON} -m pip install -U pipx
 
-# This script is run with PYTHON undefined in some places,
-# but those only use older pythons.
-if [[ -z "${PYTHON_VERSION}" ]] || [[ "${PYTHON_VERSION}" != "3.13" ]]; then
-  pipx_flags=--verbose
-  if [[ $(id -un) == "root" ]]; then
-    # Install globally as /root/.local/bin is typically not in $PATH
-    pipx_flags="${pipx_flags} --global"
-  fi
-  ${PIPX_PYTHON} -m pipx install ${pipx_flags} "https://github.com/googleapis/storage-testbench/archive/${version}.tar.gz"
+pipx_flags=(--verbose --python ${PIPX_PYTHON})
+if [[ $(id -un) == "root" ]]; then
+  # Install globally as /root/.local/bin is typically not in $PATH
+  pipx_flags+=(--global)
 fi
+if [[ -n "${PIPX_PIP_ARGS}" ]]; then
+  pipx_flags+=(--pip-args "'${PIPX_PIP_ARGS}'")
+fi
+${PIPX_BASE_PYTHON} -m pipx install ${pipx_flags[@]} \
+  "https://github.com/googleapis/storage-testbench/archive/${version}.tar.gz"

dev/tasks/python-wheels/github.osx.yml

@@ -113,6 +113,21 @@ jobs:
           name: wheel
           path: arrow/python/repaired_wheels/*.whl
 
+      # Use a well-known Python version for the GCS testbench, and avoid
+      # putting it in PATH.
+      - name: Set up Python for GCS testbench
+        uses: actions/setup-python@v5.1.1
+        id: gcs-python-install
+        with:
+          python-version: 3.12
+          update-environment: false
+
+      - name: Install GCS testbench
+        env:
+          PIPX_BIN_DIR: /usr/local/bin
+          PIPX_BASE_PYTHON: {{ '${{ steps.gcs-python-install.outputs.python-path }}' }}
+        run: arrow/ci/scripts/install_gcs_testbench.sh default
+
       - name: Test Wheel
         env:
           PYTEST_ADDOPTS: "-k 'not test_cancellation'"
@@ -121,7 +136,6 @@ jobs:
           source test-env/bin/activate
           pip install --upgrade pip wheel
           arch -{{ arch }} pip install -r arrow/python/requirements-wheel-test.txt
-          PYTHON_VERSION={{ python_version }} arch -{{ arch }} arrow/ci/scripts/install_gcs_testbench.sh default
           arch -{{ arch }} arrow/ci/scripts/python_wheel_unix_test.sh $(pwd)/arrow
 
       {{ macros.github_upload_releases("arrow/python/repaired_wheels/*.whl")|indent }}