remove pylint.extensions.emptystring plugin

This plugin was removed from pylint 3.0.0 by
pylint-dev/pylint#6871 as mentioned in the
changelog.

It is now part of the implicit booleaness checker.  Attempting to load
it causes

    ************* Module Command line or configuration file
    Command line or configuration file:1:0: E0013: Plugin 'pylint.extensions.emptystring' is impossible to load, is it installed ? ('No module named 'pylint.extensions.emptystring'') (bad-plugin-value)

Remove it.

Signed-off-by: Kevin Locke <[email protected]>

Author: kevinoid

pyproject.toml

@@ -136,7 +136,6 @@ load-plugins = [
     'pylint.extensions.bad_builtin',
     'pylint.extensions.check_elif',
     'pylint.extensions.docparams',
-    'pylint.extensions.emptystring',
     'pylint.extensions.eq_without_hash',
     'pylint.extensions.overlapping_exceptions',
     'pylint.extensions.redefined_variable_type',