docs: trivial cleanup of GL3.txt, remove redundant radeonsi entries.
docs: trivial cleanup of GL3.txt, remove redundant radeonsi entries.

Follow-up to 1b2b0e42ce47bfd1fcb5513ed2c23b9bb7a5a5b8

Signed-off-by: Kai Wasserbäch <31ea678c44dc4e8e22ccfd165592dd71a30e46ae@dev.carbon-project.org>
Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler