PEP 693, 719: Update 3.12.4 and 3.13.0b2 release dates

[hugovk]

3.12:

• https://discuss.python.org/t/python-3-12-4-now-available/55128
• https://www.python.org/downloads/release/python-3124/

3.13:

• https://discuss.python.org/t/3-13-0b2-now-available/55056
• https://www.python.org/downloads/release/python-3130b2/

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📚 Documentation preview 📚: https://pep-previews--3830.org.readthedocs.build/

[Yhg1s]

Let's see if I can review and merge while flying over the Atlantic ocean...