Use CFLAGS from the default used by the manylinux container for cibuildwheel 3.2.1

[absurdfarce]

No description provided.

[absurdfarce]

Confirmed that wheels built from this CFLAGS setting do remain smaller (as expected):

$ unzip -l cassandra_driver-3.29.3-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl | grep -i murmur
     6160  2025-12-23 23:34   cassandra/cmurmur3.c
   199168  2025-12-23 23:34   cassandra/cmurmur3.cpython-312-aarch64-linux-gnu.so
     2523  2025-12-23 23:34   cassandra/murmur3.py

[absurdfarce]

Ping @bschoening for review.

Short version of this change: the upgrade to cibuildwheel changed some of the compilation flags for native extensions. This change explicitly specifies a known-good set of flags while also including -s to strip the generated shared object.