Add `librmm` to `host` section for `rattler-build` where `librmm` is runtime dependency

[gforsyth]

When librmm was a header-only library, there was a scenario where we would include librmm in the host dependencies of the build cache, so that compilation would succeed, but leave it out of the host dependencies of the individual package outputs that were using it as a runtime dependency. Now that it isn't header-only, those outputs are now failing overlinking checks.

Issue here is to track the fixes across a few projects (luckily this isn't everything that uses librmm):

• cuml fix(rattler): add librmm to host for libcuml to fix overlinking error cuml#6686
• cudf fix(rattler): add librmm to host for libcudf to fix overlinking error cudf#18754
• cugraph fix(rattler): add librmm to host to fix overlinking errors cugraph#5065
• cumlprims_mg not needed
• ucxx not needed

[vyasr]

Closing now that all the PRs have been merged.