2.7.2rc12: Bug fixes and document updates

What's Changed

• [2.7] Fix FedOpt argument definitions by @holgerroth in #4235
• [2.7] Accept 'class_path' in component config for job API consistency by @holgerroth in #4239
• Class path component builder enhancements by @holgerroth in #4242
• [2.7] Check full Apache license header and normalize inconsistent headers by @holgerroth in #4243
• [2.7] Fix 1-18: large-model subprocess memory, reverse/forward PASS_THROUGH, download gating, MSG_ROOT_TTL, LazyRef local-aggr, logging, min_clients, diagnostics by @chesterxgchen in #4247
• [2.7] Add missing submit_model executor by @nvkevlu in #4254
• [2.7] Fix XGB cyclic by @ZiyueXu77 in #4255
• [2.7] Fix SimEnv to be compatible with strict simulator_run API by @YuanTingHsieh in #4250
• [2.7] Skip unsupported metrics for aggregation (#4223) by @holgerroth in #4252
• [2.7] Fix swarm recipe model issue by @YuanTingHsieh in #4260

Full Changelog: 2.7.2rc11...2.7.2rc12