ruby: statically link extensions into host ruby

ruby: statically link extensions into host ruby

Ruby uses extensions (.so files) that might also depend on other
libraries. When the linker builds an executable, it will refer to the
path it found the library, including those in the stagging dir. However,
when it links a shared library (like ruby exts), it will let that
dependency to be resolved at runtime.

During host and target build, ruby build script runs ruby scripts. When
it loads a ext that depends on another library, it will, by default,
look for the system libraries to satisfy that, breaking the build when
it fails. Setting LD_LIBRARY_PATH to the stagging lib dir is a valid
workaround.

Ruby can also be built statically linking all exts into ruby executable.
That will make the linker point to the stagging library path, fixing the
issue. It was used in the past but, at some point, ruby broke it. Now it
is working as expected.

Closes #20839

While at it, clean up excluded extensions not used by host ruby.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>