chore: Bump version to 4.0.0-alpha for main branch

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

appinfo/info.xml

@@ -13,7 +13,7 @@
 - **🙋 Get involved!** We have lots of stuff planned like more question types, collaboration on forms, [and much more](https://github.com/nextcloud/forms/milestones)!
 	]]></description>
 
-	<version>3.4.0</version>
+	<version>4.0.0-alpha.1</version>
 	<licence>agpl</licence>
 
 	<author>Affan Hussain</author>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "forms",
-  "version": "3.4.0",
+  "version": "4.0.0-alpha.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "forms",
-      "version": "3.4.0",
+      "version": "4.0.0-alpha.1",
       "license": "AGPL-3.0",
       "dependencies": {
         "@nextcloud/auth": "^2.2.1",

package.json

@@ -1,7 +1,7 @@
 {
   "name": "forms",
   "description": "Forms app for nextcloud",
-  "version": "3.4.0",
+  "version": "4.0.0-alpha.1",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/nextcloud/forms.git"