Set up new v18 branch

Directory.Build.props

@@ -40,8 +40,8 @@
   <!-- Package Validation -->
   <PropertyGroup>
     <GenerateCompatibilitySuppressionFile>false</GenerateCompatibilitySuppressionFile>
-    <EnablePackageValidation>true</EnablePackageValidation>
-    <PackageValidationBaselineVersion>17.0.0</PackageValidationBaselineVersion>
+    <EnablePackageValidation>false</EnablePackageValidation> <!-- TODO (V18): Set to true once this version is released. -->
+    <PackageValidationBaselineVersion>18.0.0</PackageValidationBaselineVersion>
     <EnableStrictModeForCompatibleFrameworksInPackage>true</EnableStrictModeForCompatibleFrameworksInPackage>
     <EnableStrictModeForCompatibleTfms>true</EnableStrictModeForCompatibleTfms>
   </PropertyGroup>

src/Umbraco.Web.UI.Client/package-lock.json

@@ -1,12 +1,12 @@
 {
 	"name": "@umbraco-cms/backoffice",
-	"version": "17.1.0-rc",
+	"version": "18.0.0-beta",
 	"lockfileVersion": 3,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "@umbraco-cms/backoffice",
-			"version": "17.1.0-rc",
+			"version": "18.0.0-beta",
 			"license": "MIT",
 			"workspaces": [
 				"./src/packages/*",

src/Umbraco.Web.UI.Client/package.json

@@ -1,7 +1,7 @@
 {
 	"name": "@umbraco-cms/backoffice",
 	"license": "MIT",
-	"version": "17.1.0-rc",
+	"version": "18.0.0-beta",
 	"type": "module",
 	"exports": {
 		".": null,

version.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/main/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "17.1.0-rc",
+  "version": "18.0.0-beta",
   "assemblyVersion": {
     "precision": "build"
   },
@@ -20,4 +20,4 @@
     "setVersionVariables": true,
     "setAllVariables": true
   }
-}
+}