gh-130599: precompute conversion constants for long()

[nascheme]

This avoids a data race in free-threaded builds due to mutating the static conversion arrays at runtime. Instead, compute and initialize the constants at runtime initialization. We only need to do this once (not once per interpreter) and so I added _PyLong_InitRuntime().

• Issue: long_from_non_binary_base isn't thread-safe with free threading #130599

[kumaraditya303]

You need to add the new static globals to ignored.tsv.

[nascheme]

Given that Sam expressed a preference to not compute at startup time, I investigated how that looks. It turns out that 15 and 30 are the only allowed values for PYLONG_BITS_IN_DIGIT. So statically defined constant tables are not too large. I wrote a little Python script to produce the C code, just in case we want to change any of the constants.

I updated ignored.tsv as noted by Kumar.

[kumaraditya303]

Given that Sam expressed a preference to not compute at startup time, I investigated how that looks. It turns out that 15 and 30 are the only allowed values for PYLONG_BITS_IN_DIGIT. So statically defined constant tables are not too large.

Since the table is now statically defined, it can be marked as const as it is read only.

[colesbury]

I measured the difference for ./python -c "pass" between this and the earlier commit that computed the values at runtime initialization. It's very small, about 0.1%, so I if you prefer that approach, that seems fine to me too.