GH-41002: [Python] Remove pins for pytest-cython and conda-docs pytest

[raulcd]

Rationale for this change

pytest-cython 0.3.1 was releases with the fix required for our tests to pass.

What changes are included in this PR?

Remove unnecessary dependency pinned versions.

Are these changes tested?

Via existing CI

Are there any user-facing changes?

No

• GitHub Issue: [Python] Remove pin for pytest-cython 0.2.2 #45239
• GitHub Issue: [CI][Python] Remove pins connected to pytest-cython #41002

[github-actions]

⚠️ GitHub issue #45239 has been automatically assigned in GitHub to PR creator.

[AlenkaF]

@github-actions crossbow submit -g python

[github-actions]

Revision: 2258c64

Submitted crossbow builds: ursacomputing/crossbow @ actions-ce6ceb7361

Task	Status
example-python-minimal-build-fedora-conda
example-python-minimal-build-ubuntu-venv
test-conda-python-3.10
test-conda-python-3.10-cython2
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-3.10-substrait
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

[raulcd]

CI failures are unrelated

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit fd0b94f.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 4 possible false positives for unstable benchmarks that are known to sometimes produce them.