legal: TCC and Lua license declarations

- THIRD-PARTY-NOTICES.txt gains sections for the Tiny C Compiler
  (0.9.28rc, LGPL-2.1, modified for MontaukOS; source in
  programs/src/tcc/) and Lua (5.4.8, MIT, Lua.org PUC-Rio).
- LGPL-2.1 full text ships at 0:/os/licenses/LGPL-2.1.txt (copied from
  the vendored TCC COPYING); Lua's MIT text is reproduced in the
  notices file.
- Both components added to the license's third-party list and man legal.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

programs/man/legal.7

@@ -46,5 +46,8 @@
     * Roboto font, Copyright The Roboto Project Authors - OFL-1.1
     * C059 font (URW Base 35), Copyright (C) (URW)++ Design and Development
       GmbH - AGPLv3 with font-embedding exception
+    * Tiny C Compiler (tcc.elf, 0:/lib/tcc), Copyright (c) Fabrice Bellard and
+      contributors - LGPL-2.1
+    * Lua (lua.elf, 0:/lib/lua), Copyright (C) Lua.org, PUC-Rio - MIT
 
     Full license texts and notices are on this system in 0:/os/licenses/.