gh-126647: `Doc/using/configure.rst`: Add an entry for ``--enable-experimental-jit`` option (#126648)

Add an entry for the ``--enable-experimental-jit`` option in ``Doc/using/configure.rst``.
This was added as an experimental option in CPython 3.13.
Possible values for it:
* `no` - don't build the JIT.
* `yes` - build the JIT.
* `yes-off` - build the JIT but disable it by default.
* `interpreter` - don't build the JIT but enable tier 2 interpreter instead.


Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>