Tests: Remove redundant CTestTestTimeout test

It was superseded by commit 2f5eb1800b (Tests: Add RunCMake.CTestTimeout
test, 2020-01-13, v3.17.0-rc1~169^2~1) but was kept as a dependency of
the `CTestTestRerunFailed` test.  The latter has now been moved into
`RunCMake.CTestCommandLine`, so neither is needed.