execution time should not be part of checked test output

[matthiaskrgr]

rust/tests/rustdoc-ui/doctest/doctest-no-run-invalid-langstring-124577.stdout

Line 4 in bcd0683

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

I had this one fail locally because it took 0.01s instead of 0.00s which is checked against in the test output 😆