global: Fix duplicate word typos

Used regex to find these typos:

    (?<!struct )(?<=\s)([a-z]{1,}) \1(?=\s)

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

Documentation/RelNotes/2.45.0.txt

@@ -9,7 +9,7 @@ UI, Workflows & Features
    With "git init --ref-format=reftable", hopefully it would be a lot
    more efficient to manage a repository with many references.
 
- * "git checkout -p" and friends learned that that "@" is a synonym
+ * "git checkout -p" and friends learned that "@" is a synonym
    for "HEAD".
 
  * Variants of vimdiff learned to honor mergetool.<variant>.layout

Documentation/RelNotes/2.46.0.txt

@@ -78,7 +78,7 @@ UI, Workflows & Features
    turn on cover letters automatically (unless told never to enable
    cover letter with "--no-cover-letter" and such).
 
- * The "--heads" option of "ls-remote" and "show-ref" has been been
+ * The "--heads" option of "ls-remote" and "show-ref" has been
    deprecated; "--branches" replaces "--heads".
 
  * For over a year, setting add.interactive.useBuiltin configuration