Fix commit mention font inconsistency

CHANGELOG

@@ -19,6 +19,7 @@ v 8.11.0 (unreleased)
   - Ignore URLs starting with // in Markdown links !5677 (winniehell)
   - Fix CI status icon link underline (ClemMakesApps)
   - The Repository class is now instrumented
+  - Fix commit mention font inconsistency (ClemMakesApps)
   - Fix filter label tooltip HTML rendering (ClemMakesApps)
   - Cache the commit author in RequestStore to avoid extra lookups in PostReceive
   - Expand commit message width in repo view (ClemMakesApps)

app/assets/stylesheets/framework/gfm.scss

@@ -2,7 +2,7 @@
  * Styles that apply to all GFM related forms.
  */
 
-.gfm-commit, .gfm-commit_range {
+.gfm-commit_range {
   font-family: $monospace_font;
   font-size: 90%;
 }