chore: s2 grays component-level migration (#2583)

* chore: migrate gray-50 to gray-25

Migrates any instance of `--spectrum-gray-50` to use
`--spectrum-gray-25` as per the S2 migration guide

* chore: migrate gray-75 to gray-50

Migrates usages of `--spectrum-gray-75` to use
`--spectrum-gray-50` as per the s2 migration guide.

* chore: migrate gray-100 to gray-75

Migrates usages of `--spectrum-gray-100` to use
`--spectrum-gray-75` as per the s2 migration guide

* chore: migrate gray-200 to gray-100

Migrates usages of `--spectrum-gray-200` to use
`--spectrum-gray-100` as per the s2 migration guide

* chore: migrate gray-300 to gray-200

Migrates usages of `--spectrum-gray-300` to use
`spectrum-gray-200` as per the s2 migration guide

* chore(infieldbutton): gray-300 to gray-200

components/card/index.css

@@ -119,14 +119,8 @@ governing permissions and limitations under the License.
 .spectrum-Card--quiet,
 .spectrum-Card--gallery,
 .spectrum-Card--horizontal {
-	--mod-card-preview-background-color: var(
-		--spectrum-card-preview-background-color-quiet,
-		var(--spectrum-background-base-color)
-	);
-	--spectrum-card-preview-background-color-hover: var(
-		--spectrum-card-background-color-hover-quiet,
-		var(--spectrum-gray-200)
-	);
+	--mod-card-preview-background-color: var(--spectrum-card-preview-background-color-quiet, var(--spectrum-background-base-color));
+	--spectrum-card-preview-background-color-hover: var(--spectrum-card-background-color-hover-quiet, var(--spectrum-gray-200));
 }
 
 .spectrum-Card {