.github/dependabot.yml: group @ngtools/webpack with Angular

@ngtools/webpack is provided by the Angular team and follows the
same versioning so we should group it with Angular in dependabot.

Author: alanorth

.github/dependabot.yml

@@ -23,6 +23,7 @@ updates:
         applies-to: version-updates
         patterns:
         - "@angular*"
+        - "@ngtools/webpack"
         update-types:
         - "minor"
         - "patch"
@@ -31,6 +32,7 @@ updates:
         applies-to: security-updates
         patterns:
         - "@angular*"
+        - "@ngtools/webpack"
         update-types:
         - "minor"
         - "patch"
@@ -171,6 +173,7 @@ updates:
         applies-to: version-updates
         patterns:
         - "@angular*"
+        - "@ngtools/webpack"
         update-types:
         - "minor"
         - "patch"
@@ -179,6 +182,7 @@ updates:
         applies-to: version-updates
         patterns:
         - "@ngrx*"
+        - "@ngtools/webpack"
         update-types:
         - "minor"
         - "patch"
@@ -257,6 +261,7 @@ updates:
         applies-to: version-updates
         patterns:
         - "@angular*"
+        - "@ngtools/webpack"
         update-types:
         - "minor"
         - "patch"
@@ -343,6 +348,7 @@ updates:
         applies-to: version-updates
         patterns:
         - "@angular*"
+        - "@ngtools/webpack"
         update-types:
         - "minor"
         - "patch"