Revert "Revert "Remove chardet version upper limit""

This reverts commit 09cb41c.
Original PR which removed upper bound:
datalad#7029

Debians now have 5.1.0, and we can't package while demanding an outdated
chardet. Let's see again if we really need to limit upper version.

setup.py

@@ -25,7 +25,7 @@
 requires = {
     'core': [
         'platformdirs',
-        'chardet>=3.0.4, <5.0.0',      # rarely used but small/omnipresent
+        'chardet>=3.0.4',      # rarely used but small/omnipresent
         'colorama; platform_system=="Windows"',
         'distro; python_version >= "3.8"',
         'importlib-metadata >=3.6; python_version < "3.10"',