no bug - doc: remove the reference to Semmle/LGTM r=tjr DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D189649

docs/code-quality/index.rst

@@ -43,11 +43,6 @@ In this document, we try to list these all tools.
      -
      - :ref:`cpp virtual final`
      -
-   * - Semmle/LGTM
-     -
-     - `bug 1458117 <https://bugzilla.mozilla.org/show_bug.cgi?id=1458117>`__
-     -
-     -
    * - clang-format
      - Yes
      - `bug 1188202 <https://bugzilla.mozilla.org/show_bug.cgi?id=1188202>`__