apacheGH-43883: [CI] Remove Python version guard when installing GCS …

…testbench

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

@@ -42,15 +42,14 @@ fi
 : ${PIPX_PYTHON:=$(which python3)}
 
 export PIP_BREAK_SYSTEM_PACKAGES=1
-${PIPX_PYTHON} -m pip install -U pipx
+python3 -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 $PATH
+  pipx_flags="${pipx_flags} --global"
 fi
+if [[ ! -z "${PIPX_PIP_ARGS}" ]]; then
+  pipx_flags="${pipx_flags} --pip-args '${PIPX_PIP_ARGS}'"
+fi
+python3 -m pipx install ${pipx_flags} "https://github.com/googleapis/storage-testbench/archive/${version}.tar.gz"