GH-43587: [Python] Remove no longer used serialize/deserialize PyArrow C++ code

[AlenkaF]

Rationale for this change

We deprecated serialization functionality in C++ code in #44064. We can now remove it.

What changes are included in this PR?

Serialization functionality is removed from PyArrow C++ code.

Are these changes tested?

Tests should pass.

Are there any user-facing changes?

Serialization functionality is removed from PyArrow C++ code.

• GitHub Issue: [Python] Remove no longer used serialize/deserialize PyArrow C++ code #43587

[pitrou]

@github-actions crossbow submit -g python

[pitrou]

Thanks for the update @AlenkaF ! We should also remove the corresponding declarations in pyarrow/includes/libarrow_python.pxd, no?

[github-actions]

Revision: 031ebd2

Submitted crossbow builds: ursacomputing/crossbow @ actions-593c8c5c15

Task	Status
example-python-minimal-build-fedora-conda
example-python-minimal-build-ubuntu-venv
test-conda-python-3.10
test-conda-python-3.10-hdfs-2.9.2
test-conda-python-3.10-hdfs-3.2.1
test-conda-python-3.10-pandas-latest-numpy-latest
test-conda-python-3.11
test-conda-python-3.11-dask-latest
test-conda-python-3.11-dask-upstream_devel
test-conda-python-3.11-hypothesis
test-conda-python-3.11-pandas-latest-numpy-1.26
test-conda-python-3.11-pandas-latest-numpy-latest
test-conda-python-3.11-pandas-nightly-numpy-nightly
test-conda-python-3.11-pandas-upstream_devel-numpy-nightly
test-conda-python-3.11-spark-master
test-conda-python-3.12
test-conda-python-3.12-cpython-debug
test-conda-python-3.13
test-conda-python-3.9
test-conda-python-3.9-pandas-1.1.3-numpy-1.19.5
test-conda-python-emscripten
test-cuda-python-ubuntu-22.04-cuda-11.7.1
test-debian-12-python-3-amd64
test-debian-12-python-3-i386
test-fedora-39-python-3
test-ubuntu-22.04-python-3
test-ubuntu-22.04-python-313-freethreading
test-ubuntu-24.04-python-3

[AlenkaF]

Thanks for the update @AlenkaF ! We should also remove the corresponding declarations in pyarrow/includes/libarrow_python.pxd, no?

🤦‍♀️ Will do, sorry.