Add utility classes for opacity (#33781)

* Add responsive utility classes for opacity

- fix for #33483

* remove responsive opacity utils as it has impact on bootstrap.css bundle size

* Update opacity.md

* Update site/content/docs/5.0/utilities/opacity.md

Co-authored-by: Mark Otto <otto@github.com>

* Update site/content/docs/5.0/utilities/opacity.md

Co-authored-by: Mark Otto <otto@github.com>

Co-authored-by: Harish <halodoc@ip-192-168-1-101.ap-southeast-1.compute.internal>
Co-authored-by: XhmikosR <xhmikosr@gmail.com>
Co-authored-by: Mark Otto <otto@github.com>
Co-authored-by: Mark Otto <markd.otto@gmail.com>
Co-authored-by: alpadev <2838324+alpadev@users.noreply.github.com>

scss/_utilities.scss

@@ -24,6 +24,19 @@ $utilities: map-merge(
       )
     ),
     // scss-docs-end utils-float
+    // Opacity utilities
+    // scss-docs-start utils-opacity
+    "opacity": (
+      property: opacity,
+      values: (
+        0: 0,
+        25: .25,
+        50: .5,
+        75: .75,
+        100: 1,
+      )
+    ),
+    // scss-docs-end utils-opacity
     // scss-docs-start utils-overflow
     "overflow": (
       property: overflow,