chore(crc32c): document Python 3.15 wheel support (#18442)

Release-As: 1.9.0rc0

See:
https://github.com/googleapis/release-please#how-do-i-change-the-version-number

Author: ohmayr

packages/google-crc32c/README.md

@@ -9,7 +9,7 @@ C toolchain.
 
 # Currently Published Wheels
 
-Wheels are currently published for CPython 3.10, 3.11, 3.12, 3.13 and 3.14
+Wheels are currently published for CPython 3.10, 3.11, 3.12, 3.13, 3.14 and 3.15
 for multiple architectures. PyPy 3.10 is also supported for Linux.
 For information on building your own wheels please view [BUILDING.md](BUILDING.md).