When electric-pair-mode is enabled, a single quote ' should be auto
completed to be '' (which means an empty string).  Python-mode correctly
does this, but python-ts-mode does not.  This is clearly a problem
regarding the syntax table.

The attached patch makes python-ts-mode uses the same syntax table as
python-mode's, and fixes this problem.  I also checked a few other ts
modes, and some also have this issue.  For example, js-ts-mode does not
auto complete '' either, which is also fixed by this patch.