Drop -gdwarf-4 flag from the BOLT build.

[corona10]

          Sidenote: BOLT now supports DWARF5, so there's no need to force `-gdwarf-4`

https://github.com/python/cpython/blob/main/configure.ac#L1950-1952

Originally posted by @aaupov in #101093 (comment)

Linked PRs

• gh-101278: Drop -gdwarf-4 flag from the BOLT build #101280