When 13.5-legacy is not longer supported, remove tools/signing/wrappers/sign-rcodesign

tools/signing/wrappers/sign-rcodesign is still used for signing 13.5 releases (while sign-rcodesign-128 is used for newer releases).

When we stop having 13.5-legacy releases we should remove tools/signing/wrappers/sign-rcodesign (and related files).

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information