Remove bottom padding from modal header

Add the 'pb-0' class to the modal header div in modal.component.html to remove the default bottom padding when abpHeader() is present. This fixes layout/spacing in the theme-shared modal header.

npm/ng-packs/packages/theme-shared/src/lib/components/modal/modal.component.html

@@ -2,7 +2,7 @@
 
 <ng-template #modalContent let-modal>
   @if (abpHeader()) {
-    <div id="abp-modal-header" class="modal-header abp-modal-header">
+    <div id="abp-modal-header" class="modal-header abp-modal-header pb-0">
       <ng-container *ngTemplateOutlet="abpHeader()"></ng-container>
       ​
       <button