revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/contrib/svn-fe/svn-fe.txt

@@ -56,7 +56,7 @@ line.  This line has the form `git-svn-id: URL@REVNO UUID`.
 
 The resulting repository will generally require further processing
 to put each project in its own repository and to separate the history
-of each branch.  The 'git filter-repo --subdirectory-filter' command
+of each branch.  The 'git filter-branch --subdirectory-filter' command
 may be useful for this purpose.
 
 BUGS
@@ -67,5 +67,5 @@ The exit status does not reflect whether an error was detected.
 
 SEE ALSO
 --------
-git-svn(1), svn2git(1), svk(1), git-filter-repo(1), git-fast-import(1),
+git-svn(1), svn2git(1), svk(1), git-filter-branch(1), git-fast-import(1),
 https://svn.apache.org/repos/asf/subversion/trunk/notes/dump-load-format.txt

third_party/git/contrib/svn-fe/svnrdump_sim.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python
 """
 Simulates svnrdump by replaying an existing dump from a file, taking care
 of the specified revision range.
@@ -54,7 +54,7 @@ if __name__ == "__main__":
         print("usage: %s dump URL -rLOWER:UPPER")
         sys.exit(1)
     if not sys.argv[1] == 'dump':
-        raise NotImplementedError('only "dump" is supported.')
+        raise NotImplementedError('only "dump" is suppported.')
     url = sys.argv[2]
     r = ('0', 'HEAD')
     if len(sys.argv) == 4 and sys.argv[3][0:2] == '-r':