Fedora has added multiple new targets recently, and not all are needed in RHEL. These all show up in packaging as rust-std-static-triple.

• #23 x86_64-unknown-none and x86_64-unknown-uefi.
• #27 aarch64-unknown-none-softfloat
• #34 (pending) aarch64-unknown-uefi

The only one that was directly requested for RHEL 10 was x86_64-unknown-none to enable Coconut SVSM. We can keep that one, probably shipped in the CRB repo to start, and gate the others to Fedora-only until we see a business need for them.