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/Documentation/config/format.txt

@@ -36,12 +36,6 @@ format.subjectPrefix::
 	The default for format-patch is to output files with the '[PATCH]'
 	subject prefix. Use this variable to change that prefix.
 
-format.coverFromDescription::
-	The default mode for format-patch to determine which parts of
-	the cover letter will be populated using the branch's
-	description. See the `--cover-from-description` option in
-	linkgit:git-format-patch[1].
-
 format.signature::
 	The default for format-patch is to output a signature containing
 	the Git version number. Use this variable to change that default.
@@ -83,11 +77,10 @@ format.coverLetter::
 	A boolean that controls whether to generate a cover-letter when
 	format-patch is invoked, but in addition can be set to "auto", to
 	generate a cover-letter only when there's more than one patch.
-	Default is false.
 
 format.outputDirectory::
 	Set a custom directory to store the resulting files instead of the
-	current working directory. All directory components will be created.
+	current working directory.
 
 format.useAutoBase::
 	A boolean value which lets you enable the `--base=auto` option of
@@ -106,20 +99,4 @@ If one wishes to use the ref `ref/notes/true`, please use that literal
 instead.
 +
 This configuration can be specified multiple times in order to allow
-multiple notes refs to be included. In that case, it will behave
-similarly to multiple `--[no-]notes[=]` options passed in. That is, a
-value of `true` will show the default notes, a value of `<ref>` will
-also show notes from that notes ref and a value of `false` will negate
-previous configurations and not show notes.
-+
-For example,
-+
-------------
-[format]
-	notes = true
-	notes = foo
-	notes = false
-	notes = bar
-------------
-+
-will only show notes from `refs/notes/bar`.
+multiple notes refs to be included.