message: Fix `sticky-file-header` overlap and position
diff: -:root .file-header {
  +/* `.sticky-file-header` excludes native sticky header */
  +:root .file-header:not(.sticky-file-header) {
  position: sticky;
  z-index: 6; /* isBlame, isEditingFile */
  top: 0;
  top: 129px;
  }
  +/* Same as `.sticky-file-header.has-open-dropdown` */
  +.file-header.has-open-dropdown:not(.sticky-file-header) {
  + z-index: 10;
  +}
  +
  /* Consider the File List fixed header/sidebar in commits */
  -:root diff-layout .file-header {
  +:root diff-layout .file-header:not(.sticky-file-header) {
  top: 60px;
  }
  @@ -22,5 +28,5 @@ https://github.com/refined-github/refined-github/edit/main/readme.md
  https://github.com/refined-github/refined-github/blame/243e51d786e4771d313091b94cec826ff86becc9/source/features/index.tsx#L326-L327
  Exclude:
  -https://github.com/refined-github/refined-github/pull/5460/files (actually included, but natively supported anyway)
  +https://github.com/refined-github/refined-github/pull/5460/files
  */
  