ceph.spec.in: openSUSE: require gcc11-c++, disable parquet

ceph.spec.in: openSUSE: require gcc11-c++, disable parquet

This commit also explicilty sets the toolset when calling
boost's bootstrap.sh, because the latter is only capable
of autodetecting gcc if you have an unversioned `g++` in
the path, which may not be the case if only gcc11-c++ is
installed (the unversioned gcc-c++ package includes the
/usr/bin/g++ symlink, but depending on which version of
openSUSE we build on, that might point to a different gcc
version, so we don't want to use that).

Fixes: https://tracker.ceph.com/issues/55237
Signed-off-by: Tim Serong <tserong@suse.com>