Update pandas version upper bound to support python 3.14

[shunping]

Bump pandas version to 2.3.x to fix segfault on dataframe tests that run on python 3.14.

Stacktrace of segfault from failed tests: https://github.com/apache/beam/actions/runs/27927544557/job/82678205191

Current thread 0x00000002066c22c0 (most recent call first):
  File "/Users/runner/work/beam/beam/sdks/python/target/.tox/py314-macos/lib/python3.14/site-packages/pandas/core/arrays/datetimes.py", line 439 in _generate_range
  File "/Users/runner/work/beam/beam/sdks/python/target/.tox/py314-macos/lib/python3.14/site-packages/pandas/core/indexes/datetimes.py", line 1008 in date_range
  File "/Users/runner/work/beam/beam/sdks/python/apache_beam/dataframe/frames_test.py", line 796 in test_loc
  File "/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/unittest/case.py", line 615 in _callTestMethod
  File "/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/unittest/case.py", line 669 in run
  File "/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/unittest/case.py", line 725 in __call__

This failure occurs when running the tests with pandas 2.2.3, whereas pandas 2.3.3 is the first version to introduce support for Python 3.14 (https://github.com/pandas-dev/pandas/releases/tag/v2.3.3).

Also see #38691 (comment)

---

Notice that a few tests failed (https://github.com/apache/beam/actions/runs/27951859585/job/82710533408?pr=39056) due to a change in pandas 2.3.0+, where null/missing values returned
by Series.str.get_dummies() are changed from 'nan' to 'NaN'.

• 2.2.x: https://github.com/pandas-dev/pandas/blob/2.2.x/pandas/core/arrays/categorical.py#L2699
• 2.3.x: https://github.com/pandas-dev/pandas/blob/2.3.x/pandas/core/arrays/categorical.py#L2738

In this PR, we also applied a fix in the code so the tests pass on pandas before and after 2.3.0.

Also related to #31238.

[shunping]

r: @tvalentyn

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Summary of Changes

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This pull request updates the project's pandas dependency to support Python 3.14, addressing critical segmentation faults encountered during testing. It includes necessary adjustments to handle behavioral changes in pandas 2.3.0+ regarding how null values are represented in dummy columns, ensuring the codebase remains compatible with both older and newer versions of the library.

Highlights

• Dependency Update: Updated the pandas version upper bound from <2.3 to <2.4 in setup.py to support Python 3.14 and resolve segmentation faults.
• Compatibility Fix: Implemented dynamic detection of the NaN column name in get_dummies() to ensure compatibility across different pandas versions (2.2.x vs 2.3.x+).
• Test Infrastructure: Introduced PD_FULL_VERSION to allow for more granular version checks in test suites, ensuring robust test execution across pandas releases.

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Code Review

This pull request updates the pandas dependency constraint to support versions up to <2.4, adjusts test skip conditions to use a full version check, and dynamically detects the NaN column name used by pandas in get_dummies(). The feedback suggests replacing the dynamic pandas operation with a static version check to avoid runtime overhead and potential IndexError.

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