docs: add sha256 checksums for 11.2.1
docs: add sha256 checksums for 11.2.1

Signed-off-by: Emil Velikov <f20878473f414da183da19ee25c8722cc1d711e4@collabora.com>
(cherry picked from commit c65835d81230fbdc1544600c0a24f90647a4e75a)

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler