regex 1.12.3: non-fuzzing test data accidentally excluded

[decathorpe]

followup for #1319

It appears that the package.include setting added in this PR is too strict, as it caused some data files that are used by regular / non-fuzzing tests in regex to get excluded as well.

As far as I can tell, the only three files missing now are testdata/fowler/*.toml.

It looks like they were intended to be included (by the "testdata/**.toml" glob), but the syntax for this glob seems to be wrong (should be testdata/**/*.toml instead, as far as I can tell).