Removed unused GlobalAvergaPooling internal code. #3163

Job	Run time
build-and-test / cmake-linux-armhf	6m 12s
build-and-test / cmake-linux-riscv64-rvv	12m 5s
build-and-test / cmake-linux-aarch64	7m 44s
build-and-test / cmake-linux-riscv64	5m 34s
build-and-test / cmake-linux-x86_64	9m 40s
build-and-test / bazel-linux-aarch64	10m 35s
build-and-test / bazel-linux-x86_64-clang-18	11m 36s
build-and-test / bazel-linux-x86_64-gcc-9	7m 18s
build-and-test / cmake-android (arm64)	8m 7s
build-and-test / cmake-android (armv7)	6m 22s
build-and-test / cmake-ios-x86_64	6m 28s
build-and-test / cmake-ios-arm64	5m 7s
build-and-test / cmake-android (x86)	8m 57s
build-and-test / cmake-macos-arm64	6m 29s
build-and-test / cmake-windows-arm64	2m 52s
build-and-test / cmake-windows-x64	5m 19s
build-and-test / cmake-windows-x86	6m 37s
	2h 7m 2s

Provide feedback