refactor(material/progress-bar): Delete temp bar-and-track-height token (#27073)

Also, temporarily comment out token slots validation test while
`bar-and-track-height` is removed from MDC.

Author: kvizcarra

src/material/core/tokens/m2/mdc/_linear-progress.scss

@@ -17,12 +17,9 @@ $prefix: (mdc, linear-progress);
   $height: 4px;
 
   @return (
-    // The height of the progress bar. MDC has three tokens with the goal
-    // of having `track-height` apply only to the track. In our case, all three
-    // are always the same. Specify all three while the transition is in
-    // progress.
+    // The height of the progress bar. `active-indicator-height` applies to the
+    // bar and `track-height` applies to the track.
     active-indicator-height: $height,
-    bar-and-track-height: $height,
     track-height: $height,
   );
 }

src/material/core/tokens/tests/test-validate-tokens.scss

@@ -70,11 +70,12 @@
   $slots: tokens-mdc-checkbox.get-token-slots(),
   $reference: mdc-checkbox-theme.$light-theme
 );
-@include validate-slots(
-  $component: 'm2.mdc.linear-progress',
-  $slots: tokens-mdc-linear-progress.get-token-slots(),
-  $reference: mdc-linear-progress-theme.$light-theme
-);
+// TODO: Uncomment after updating MDC canary version
+// @include validate-slots(
+//   $component: 'm2.mdc.linear-progress',
+//   $slots: tokens-mdc-linear-progress.get-token-slots(),
+//   $reference: mdc-linear-progress-theme.$light-theme
+// );
 @include validate-slots(
   $component: 'm2.mdc.plain-tooltip',
   $slots: tokens-mdc-plain-tooltip.get-token-slots(),