Update core tests; check fnmatch for nested braces

[cxw42]

Re. https://github.com/editorconfig/editorconfig-core-py/pull/33

• [x] Update to the latest core tests
• [x] See if the tests pass!
• [x] If not, update fnmatch.

The Vimscript core is mostly a port of the Python core. The above-noted PR fixed a bug in the Python core that may also exist in the Vimscript core.

[cxw42]

As of today, the nested-brace tests fail:

The following tests FAILED:
         55 - braces_nested_start1 (Failed)
         57 - braces_nested_start3 (Failed)
         58 - braces_nested_start4 (Failed)
         59 - braces_nested_start5 (Failed)
         60 - braces_nested_end1 (Failed)
         62 - braces_nested_end3 (Failed)
         63 - braces_nested_end4 (Failed)
         64 - braces_nested_end5 (Failed)

A single test:

$ EDITORCONFIG_DEBUG=`realpath foo.txt` /home/cxw/proj/editorconfig-vim/tests/core/editorconfig "-f" "braces.in" "/home/cxw/proj/editorconfig-vim/tests/core/tests/glob/a.k"

should match but doesn't. Debug file foo.txt says:

- fnmatch#fnmatchcase: regex    \v\/home\/cxw\/proj\/editorconfig\-vim\/tests\/core\/tests\/glob\_.*\/\{\{a\,b\}\,c\}\.k\_$

I don't think the regex should have escaped braces.

Edit Indeed, the problem and fix were the same as in the Python core.