MDL-78052 theme: Update FontAwesome to 6.4.0

This version also fixes a regression in 6.3.0 where a number of
icons weren't centered properly in their viewboxes.

lib/thirdpartylibs.xml

@@ -458,7 +458,7 @@ All rights reserved.</copyright>
     <location>fonts</location>
     <name>Font Awesome - http://fontawesome.com</name>
     <description>The Font Awesome font. Font Awesome is the Internet's icon library and toolkit, used by millions of designers, developers, and content creators.</description>
-    <version>6.3.0</version>
+    <version>6.4.0</version>
     <license>SIL OFL</license>
     <licenseversion>1.1</licenseversion>
     <repository>https://github.com/FortAwesome/Font-Awesome</repository>

theme/boost/scss/fontawesome/brands.scss

@@ -1,5 +1,5 @@
 /*!
- * Font Awesome Free 6.3.0 by @fontawesome - https://fontawesome.com
+ * Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com
  * License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License)
  * Copyright 2023 Fonticons, Inc.
  */
@@ -16,9 +16,8 @@
   font-style: normal;
   font-weight: 400;
   font-display: $fa-font-display;
-  src:
-    url('[[font:core|fa-brands-400.woff2]]') format('woff2'),
-    url('[[font:core|fa-brands-400.ttf]]') format('truetype');
+  src: url('#{$fa-font-path}/fa-brands-400.woff2') format('woff2'),
+    url('#{$fa-font-path}/fa-brands-400.ttf') format('truetype');
 }
 
 .fab,

theme/boost/scss/fontawesome/fontawesome.scss

@@ -1,5 +1,5 @@
 /*!
- * Font Awesome Free 6.3.0 by @fontawesome - https://fontawesome.com
+ * Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com
  * License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License)
  * Copyright 2023 Fonticons, Inc.
  */

theme/boost/scss/fontawesome/regular.scss

@@ -1,5 +1,5 @@
 /*!
- * Font Awesome Free 6.3.0 by @fontawesome - https://fontawesome.com
+ * Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com
  * License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License)
  * Copyright 2023 Fonticons, Inc.
  */
@@ -16,9 +16,8 @@
   font-style: normal;
   font-weight: 400;
   font-display: $fa-font-display;
-  src:
-    url('[[font:core|fa-regular-400.woff2]]') format('woff2'),
-    url('[[font:core|fa-regular-400.ttf]]') format('truetype');
+  src: url('#{$fa-font-path}/fa-regular-400.woff2') format('woff2'),
+    url('#{$fa-font-path}/fa-regular-400.ttf') format('truetype');
 }
 
 .far,

theme/boost/scss/fontawesome/solid.scss

@@ -1,5 +1,5 @@
 /*!
- * Font Awesome Free 6.3.0 by @fontawesome - https://fontawesome.com
+ * Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com
  * License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License)
  * Copyright 2023 Fonticons, Inc.
  */
@@ -16,9 +16,8 @@
   font-style: normal;
   font-weight: 900;
   font-display: $fa-font-display;
-  src:
-    url('[[font:core|fa-solid-900.woff2]]') format('woff2'),
-    url('[[font:core|fa-solid-900.ttf]]') format('truetype');
+  src: url('#{$fa-font-path}/fa-solid-900.woff2') format('woff2'),
+    url('#{$fa-font-path}/fa-solid-900.ttf') format('truetype');
 }
 
 .fas,

theme/boost/scss/fontawesome/v4-shims.scss

@@ -1,5 +1,5 @@
 /*!
- * Font Awesome Free 6.3.0 by @fontawesome - https://fontawesome.com
+ * Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com
  * License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License)
  * Copyright 2023 Fonticons, Inc.
  */
@@ -9,18 +9,3 @@
 @import 'functions';
 @import 'variables';
 @import 'shims';
-
-:root, :host {
-    --#{$fa-css-prefix}-style-family-brands: 'Font Awesome 4 Compatibility';
-    --#{$fa-css-prefix}-font-brands: normal 400 1em/1 'Font Awesome 4 Compatibility';
-  }
-
-  @font-face {
-    font-family: 'Font Awesome 4 Compatibility';
-    font-style: normal;
-    font-weight: 400;
-    font-display: $fa-font-display;
-    src:
-      url('[[font:core|fa-v4compatibility.woff2]]') format('woff2'),
-      url('[[font:core|fa-v4compatibility.ttf]]') format('truetype');
-  }

theme/boost/thirdpartylibs.xml

@@ -199,7 +199,7 @@
     <location>scss/fontawesome</location>
     <name>Font Awesome - http://fontawesome.com</name>
     <description>Font Awesome CSS, LESS, and Sass files. Font Awesome is the Internet's icon library and toolkit, used by millions of designers, developers, and content creators.</description>
-    <version>6.3.0</version>
+    <version>6.4.0</version>
     <license>(MIT)</license>
     <repository>https://github.com/FortAwesome/Font-Awesome</repository>
     <copyrights>