Tests: Simplify RunCMake.CPack_RPM.SUGGESTS expected output

Drop an optional part of the output that is never printed anymore.

Tests/RunCMake/CPack/tests/SUGGESTS/RPM-stderr.txt

@@ -1 +1 @@
-^(.*CPackRPM:Warning: SUGGESTS not supported in provided rpmbuild.*)?CPackRPM: Will use GENERATED spec file: (/[^/]*)*/Tests/RunCMake/RPM\.SUGGESTS/CPack/[^-]*-build/_CPack_Packages/.*/RPM/SPECS/[^\.]*\.spec$
+^CPackRPM: Will use GENERATED spec file: (/[^/]*)*/Tests/RunCMake/RPM\.SUGGESTS/CPack/[^-]*-build/_CPack_Packages/.*/RPM/SPECS/[^\.]*\.spec$