fix: ensure compat with site editor

packages/block-library/package.json

@@ -45,7 +45,6 @@
 		"@wordpress/date": "file:../date",
 		"@wordpress/deprecated": "file:../deprecated",
 		"@wordpress/dom": "file:../dom",
-		"@wordpress/editor": "file:../editor",
 		"@wordpress/element": "file:../element",
 		"@wordpress/escape-html": "file:../escape-html",
 		"@wordpress/hooks": "file:../hooks",

packages/block-library/src/post-template/edit.js

@@ -19,7 +19,6 @@ import {
 } from '@wordpress/block-editor';
 import { Spinner, ToolbarGroup } from '@wordpress/components';
 import { store as coreStore } from '@wordpress/core-data';
-import { store as editorStore } from '@wordpress/editor';
 import { list, grid } from '@wordpress/icons';
 
 const TEMPLATE = [
@@ -111,7 +110,16 @@ export default function PostTemplateEdit( {
 		( select ) => {
 			const { getEntityRecords, getTaxonomies } = select( coreStore );
 			const { getBlocks } = select( blockEditorStore );
-			const { getCurrentPostId } = select( editorStore );
+			// @wordpress/block-library should not depend on @wordpress/editor.
+			// Blocks can be loaded into a *non-post* block editor, so to avoid
+			// declaring @wordpress/editor as a dependency, we must access its
+			// store by string.
+			// getCurrentPostId also returns a string in the site editor and a
+			// number in the post editor, it's only useful to us if it's a number.
+			const currentPostId = parseInt(
+				// eslint-disable-next-line @wordpress/data-no-store-string-literals
+				select( 'core/editor' )?.getCurrentPostId()
+			);
 			const templateCategory =
 				inherit &&
 				templateSlug?.startsWith( 'category-' ) &&
@@ -163,11 +171,11 @@ export default function PostTemplateEdit( {
 			if ( exclude?.length ) {
 				query.exclude = exclude;
 			}
-			if ( excludeCurrent ) {
+			if ( excludeCurrent && currentPostId ) {
 				if ( query.exclude ) {
-					query.exclude = [ ...query.exclude, getCurrentPostId() ];
+					query.exclude = [ ...query.exclude, currentPostId ];
 				} else {
-					query.exclude = [ getCurrentPostId() ];
+					query.exclude = [ currentPostId ];
 				}
 			}
 			if ( parents?.length ) {