Tests: Fix RunCMake.CTest to tolerate source line number changes

Tests/RunCMake/CTest/BeforeProject-stderr.txt

@@ -1,6 +1,6 @@
 CMake Error at .*/Modules/CTestTargets.cmake:20 \(message\):
   Do not include\(CTest\) before calling project\(\).
 Call Stack \(most recent call first\):
-  .*/Modules/CTest.cmake:297 \(include\)
+  .*/Modules/CTest.cmake:[0-9]+ \(include\)
   BeforeProject.cmake:1 \(include\)
   CMakeLists.txt:5 \(include\)