changelog-generator: Fixed syntax error in regex

Fixed a syntax error in changelog-generator script regex by making it a
raw string. The syntax error appeared while executing the script with
Python 3.12.3.

Signed-off-by: Lars Erik Wik <[email protected]>

Author: larsewi

misc/changelog-generator/changelog-generator

@@ -189,7 +189,7 @@ for repo in repos:
                             del ENTRIES[linked_sha]
                     continue
 
-            match = re.match("^\(cherry picked from commit ([0-9a-f]+)\)", line, re.IGNORECASE)
+            match = re.match(r"^\(cherry picked from commit ([0-9a-f]+)\)", line, re.IGNORECASE)
             if match:
                 if log_entry:
                     add_entry(sha, log_entry)