Tests/RunCMake/RuntimePath: Fix Stub case for musl C library

Fixes: #26565

Tests/RunCMake/RuntimePath/Stub-fail-stderr.txt

@@ -1 +1 @@
-(error while loading shared libraries: libStub\.so\.1|Library not loaded: '?@rpath/libStub\.1\.dylib'?|(Cannot|Could not) load module libStub\.a\(libStub\.so\.1\)|fatal: libStub\.so\.1: open failed|Shared object "libStub\.so\.1" not found)
+(error while loading shared libraries: libStub\.so\.1|Library not loaded: '?@rpath/libStub\.1\.dylib'?|(Cannot|Could not) load module libStub\.a\(libStub\.so\.1\)|fatal: libStub\.so\.1: open failed|Shared object "libStub\.so\.1" not found|Error loading shared library libStub\.so\.1:)