[libomp][AIX] Ensure only libomp.a is published on AIX (#109016)

For `libomp` on AIX, we build shared object `libomp.so` first and then
archive it into `libomp.a`. Due to a CMake for AIX problem, the install
step also tries to publish `libomp.so`. While we use a script to build
`libomp.a` out-of-tree for Clang and avoided the problem, this chokes
the in-tree build for Flang. The issue will be reported to CMake but
before a fixed CMake is available, this patch ensures only `libomp.a` is
published.

GitOrigin-RevId: bde51d9b0d473447ea12fb14924f14ea167eec85
1 file changed