[stable-2.9] Document existing ansi_re sequences and add `ESC[m` (#70683) (#70808)

* Document existing ansi_re sequences and add `ESC[m`

* Add changelog
(cherry picked from commit 06a4fc2)

Co-authored-by: Nathaniel Case <ncase@redhat.com>

changelogs/fragments/70683-terminal-ansi-re.yaml

@@ -0,0 +1,3 @@
+---
+bugfixes:
+  - Terminal plugins - add "\e[m" to the list of ANSI sequences stripped from device output

lib/ansible/plugins/terminal/__init__.py

@@ -48,8 +48,9 @@ class TerminalBase(with_metaclass(ABCMeta, object)):
 
     #: compiled bytes regular expressions to remove ANSI codes
     ansi_re = [
-        re.compile(br'(\x1b\[\?1h\x1b=)'),
+        re.compile(br'\x1b\[\?1h\x1b='),  # CSI ? 1 h ESC =
-        re.compile(br'\x08.')
+        re.compile(br'\x08.'),            # [Backspace] .
+        re.compile(br"\x1b\[m"),          # ANSI reset code
     ]
 
     #: terminal initial prompt