python3: bump to 3.14.5

python3: bump to 3.14.5

This is the latest 3.14.x point release with assorted bug fixes
from upstream. PYTHON3_PIP_VERSION is bumped from 26.0.1 to 26.1.1
to match the pip wheel bundled in the 3.14.5 source tarball; the
host build's ensurepip lookup of pip-$(PYTHON3_PIP_VERSION).whl
otherwise fails. The set of OpenWrt-side patches still applies
against the new source; only quilt context-line offsets needed
refreshing for the patches that touch Makefile.pre.in.

Signed-off-by: Alexandru Ardelean <redacted>