GH-36200: [CI][Docs] Avoid "No space left on device" (#36230)

### Rationale for this change

Our build requires many disk space.

### What changes are included in this PR?

Remove unused files.

### Are these changes tested?

Yes.

### Are there any user-facing changes?

No.
* Closes: #36200

Authored-by: Sutou Kouhei <kou@clear-code.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>

.github/workflows/docs.yml

@@ -22,7 +22,7 @@ on:
 
 permissions:
   contents: read
-  
+
 env:
   ARROW_ENABLE_TIMING_TESTS: OFF
   DOCKER_VOLUME_PREFIX: ".docker/"

ci/docker/conda-python.dockerfile

@@ -45,6 +45,7 @@ ENV ARROW_ACERO=ON \
     ARROW_CSV=ON \
     ARROW_DATASET=ON \
     ARROW_FILESYSTEM=ON \
+    ARROW_GDB=ON \
     ARROW_HDFS=ON \
     ARROW_JSON=ON \
     ARROW_TENSORFLOW=ON \

ci/docker/ubuntu-20.04-cpp.dockerfile

@@ -108,6 +108,7 @@ RUN apt-get update -y -q && \
         python3-dev \
         python3-pip \
         python3-rados \
+        python3-venv \
         rados-objclass-dev \
         rapidjson-dev \
         rsync \

ci/docker/ubuntu-22.04-cpp.dockerfile

@@ -107,6 +107,7 @@ RUN apt-get update -y -q && \
         protobuf-compiler-grpc \
         python3-dev \
         python3-pip \
+        python3-venv \
         rapidjson-dev \
         rsync \
         tzdata \

ci/scripts/cpp_build.sh

@@ -40,6 +40,19 @@ elif [ -x "$(command -v xcrun)" ]; then
   export ARROW_GANDIVA_PC_CXX_FLAGS="-isysroot;$(xcrun --show-sdk-path)"
 fi
 
+if [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
+  case "$(uname)" in
+    Linux|Darwin|MINGW*)
+      if [ "${ARROW_GDB:-OFF}" != "ON" ]; then
+        : ${ARROW_C_FLAGS_DEBUG:=-g1}
+        : ${ARROW_CXX_FLAGS_DEBUG:=-g1}
+      fi
+      ;;
+    *)
+      ;;
+  esac
+fi
+
 if [ "${ARROW_USE_CCACHE}" == "ON" ]; then
     echo -e "===\n=== ccache statistics before build\n==="
     ccache -sv 2>/dev/null || ccache -s