chore: bump version to v4.0.0-beta2

Author: itsnebulalol

external/board/nocturne/rootfs_overlay/etc/nocturne/version.json

@@ -1,6 +1,6 @@
 {
-    "version": "v4.0.0-${GIT_HASH}",
-    "shortVersion": "v4.0.0",
+    "version": "v4.0.0-beta2-${GIT_HASH}",
+    "shortVersion": "v4.0.0-beta2",
     "gitHash": "${GIT_HASH}",
     "buildDate": "${BUILD_DATE}"
 }