textcode markup: fix SyntaxWarning in regex

Signed-off-by: Maxwell G <maxwell@gtmx.me>

Author: gotmax23

CHANGELOG.rst

@@ -37,6 +37,8 @@ v33.0.0 (next next, roadmap)
 - Update link references of ownership from nexB to aboutcode-org
   See https://github.com/aboutcode-org/scancode-toolkit/issues/3885
 
+- Fix Python ``SyntaxWarning`` in extractcode module.
+
 
 v32.2.1 - 2024-07-02
 ---------------------

src/textcode/markup.py

@@ -118,7 +118,7 @@ def demarkup(location):
     r'|'
     r'href'
     r'|'
-    '[\'"]?\/\>'
+    r'[\'"]?\/\>'
     r'|'
     r'/>'
     r')',