Fix test_doctest.test_number_non_matches
Fix test_doctest.test_number_non_matches

These doctests were expected to fail, but they were failing because of a
silly bug (I forgot to replace "{expression}" with the actual expression
to be tested), not because of the thing they were meant to be testing.

Then I had to fix one of the testcases because it was actually matching:

    >>> 3.0 #doctest: +NUMBER
    2.99

The doctest is saying that the actual output should match to 2 decimal
places, i.e. within 0.01 -- which it is, so it passes. I changed the
expected output to 2.98 and now it doesn't match (as we expect).

The-Compiler/pytest,RonnyPfannschmidt/pytest,nicoddemus/pytest,tomviner/pytest,pytest-dev/pytest,Akasurde/pytest,nicoddemus/pytest,tomviner/pytest,The-Compiler/pytest,alfredodeza/pytest,markshao/pytest