www/apache24: Add GDBM option

This adds a GDBM option which defaults to on and makes the libgdm
dependency conditional on that option.

Clean up removed TLS module

PR: 291447
Differential Revision: https://reviews.freebsd.org/D56843
MFH: 2026Q2

(cherry picked from commit 0527e6e893b978cc44b770424df0cd53f392e799)