Drop Legacy Edge support.

This allows us to move forward without being held back. Microsoft already replaces the Legacy Edge with the new one on supported Windows versions.

site/content/docs/5.0/forms/floating-labels.md

@@ -10,8 +10,6 @@ toc: true
 
 Wrap a pair of `<input class="form-control">` and `<label>` elements in `.form-floating` to enable floating labels with Bootstrap's textual form fields. A `placeholder` is required on each `<input>` as our method of CSS-only floating labels uses the `:placeholder-shown` pseudo-element. Also note that the `<input>` must come first so we can utilize a sibling selector (e.g., `~`).
 
-This approach works in the new Microsoft Edge built on Chromium and gracefully degrades on older versions.
-
 {{< example >}}
 <div class="form-floating mb-3">
   <input type="email" class="form-control" id="floatingInput" placeholder="name@example.com">

site/content/docs/5.0/getting-started/browsers-devices.md

@@ -8,7 +8,7 @@ toc: true
 
 ## Supported browsers
 
-Bootstrap supports the **latest, stable releases** of all major browsers and platforms. This also includes the latest version of Legacy Edge (EdgeHTML layout engine).
+Bootstrap supports the **latest, stable releases** of all major browsers and platforms.
 
 Alternative browsers which use the latest version of WebKit, Blink, or Gecko, whether directly or via the platform's web view API, are not explicitly supported. However, Bootstrap should (in most cases) display and function correctly in these browsers as well. More specific support information is provided below.
 

site/content/docs/5.0/migration.md

@@ -9,6 +9,10 @@ toc: true
 
 ## v5.0.0-alpha3
 
+### Browser support
+
+- Dropped support for Microsoft Edge Legacy. See [here](#browser-support-1) for the previous browser support changes.
+
 ### Colors
 
 - The color system which worked with `color-level()` and `$theme-color-interval` was removed in favor of a new color system.