Replace manual version.py stamping with scikit-build-core's
setuptools_scm metadata provider, so local builds no longer call
version.py. The Python distribution/runtime version comes from the
generated python/tvm/_version.py (libinfo.py reads it with a fallback);
the C++ TVM_VERSION is injected from SKBUILD_PROJECT_VERSION_FULL with a
#ifndef default in base.h for bare cmake builds.
version.py is removed. The publish workflow's wheel build checks out
full history (fetch-depth: 0) so setuptools_scm can derive the version,
and drops the version.py stamping step. release_process.rst is updated
to the tag-driven release flow.
Shushi Hong
a72d57c616