remove{suffix,prefix} replaces {l,r}strip in pytorch/text/torchtext/datasets/cc100.py +1

Summary:
`x.lstrip("string")` is equivalent to `re.sub(r"[string]", "", x)`. This means that `"fbcode/fbcode_file".lstrip("fbcode/")` returns `_file`. This can easily be an unintended behaviour!

Instead, as of Python 3.10, we should use `string.removeprefix` or `string.removesuffix`.

This diff makes one or more such fixes that we believe are likely to be bugs. Please double-check before approving.

Reviewed By: itamaro, zsol

Differential Revision: D55386410

fbshipit-source-id: 903b7e2b6825bd6489e211b1837fa4a65d12ca91

Author: r-barnes

torchtext/datasets/cc100.py

@@ -138,7 +138,7 @@ def _filepath_fn(root, url, _=None):
 
 
 def _decompressed_filepath_fn(root, x):
-    return os.path.join(root, os.path.basename(x).rstrip(".xz"))
+    return os.path.join(root, os.path.basename(x).removesuffix(".xz"))
 
 
 def _modify_res(language_code, x):