GH-49138: [Packaging][Python] Remove nightly cython install from manylinux wheel dockerfile (#49139)

### Rationale for this change

We use nightlies version of Cython for free-threaded PyArrow wheels and they are currently failing, see #49138

### What changes are included in this PR?

Nightly Cython install is removed and Cython is installed via [requirements file](https://github.com/apache/arrow/blob/main/python/requirements-wheel-build.txt#L2).

### Are these changes tested?
Tes.

### Are there any user-facing changes?
No.
* GitHub Issue: #49138

Authored-by: AlenkaF <frim.alenka@gmail.com>
Signed-off-by: AlenkaF <frim.alenka@gmail.com>

Author: AlenkaF

ci/docker/python-wheel-manylinux.dockerfile

@@ -113,10 +113,5 @@ RUN PYTHON_ROOT=$(find /opt/python -name cp${PYTHON_VERSION/./}-${PYTHON_ABI_TAG
 SHELL ["/bin/bash", "-i", "-c"]
 ENTRYPOINT ["/bin/bash", "-i", "-c"]
 
-# Remove once there are released Cython wheels for 3.13 free-threaded available
-RUN if [ "${python_abi_tag}" = "cp313t" ]; then \
-      pip install cython --pre --extra-index-url "https://pypi.anaconda.org/scientific-python-nightly-wheels/simple" --prefer-binary ; \
-    fi
-
 COPY python/requirements-wheel-build.txt /arrow/python/
 RUN pip install -r /arrow/python/requirements-wheel-build.txt

ci/scripts/python_wheel_macos_build.sh

@@ -46,12 +46,6 @@ else
   exit 1
 fi
 
-# Remove once there are released Cython wheels for 3.13 free-threaded available
-FREE_THREADED_BUILD="$(python -c"import sysconfig; print(bool(sysconfig.get_config_var('Py_GIL_DISABLED')))")"
-if [[ $FREE_THREADED_BUILD == "True"  ]]; then
-  pip install cython --pre --extra-index-url "https://pypi.anaconda.org/scientific-python-nightly-wheels/simple" --prefer-binary
-fi
-
 pip install \
   --force-reinstall \
   --only-binary=:all: \