gh-91421: Use constant value check during runtime (GH-91422) (GH-91493)

gh-91421: Use constant value check during runtime (GH-91422) (GH-91493)

The left-hand side expression of the if-check can be converted to a
constant by the compiler, but the addition on the right-hand side is
performed during runtime.

Move the addition from the right-hand side to the left-hand side by
turning it into a subtraction there. Since the values are known to
be large enough to not turn negative, this is a safe operation.

Prevents a very unlikely integer overflow on 32 bit systems.

Fixes GH-91421.
(cherry picked from commit 0859368335d470b9ff33fc53ed9a85ec2654b278)

Co-authored-by: Tobias Stoeckmann <stoeckmann@users.noreply.github.com>
Origin: upstream, https://github.com/python/cpython/commit/edf1a77f239069235f59103cfd8ce7f939c7fd10

Gbp-Pq: Name CVE-2025-4516-3.patch