os.path.commonprefix() is deprecated

[stefan6419846]

Running code from this package on Python 3.15 raises deprecation warning:

/opt/hostedtoolcache/Python/3.15.0-rc.2/x64/lib/python3.15/site-packages/typecode/_vendor/pygments/regexopt.py:58: DeprecationWarning: os.path.commonprefix() is deprecated. Use os.path.commonpath() for longest path prefix.
  prefix = commonprefix(strings)
/opt/hostedtoolcache/Python/3.15.0-rc.2/x64/lib/python3.15/site-packages/typecode/_vendor/pygments/regexopt.py:68: DeprecationWarning: os.path.commonprefix() is deprecated. Use os.path.commonpath() for longest path prefix.
  suffix = commonprefix(strings_rev)

Upstream fix: pygments/pygments#3040