Incrementing VERSION to 120.0.6076.3

Change-Id: Ie080afc37237e1c56884179af1df4769fda961c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4953735
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/6076@{#5}
Cr-Branched-From: 65ba1ef-refs/heads/main@{#1211682}

chrome/VERSION

@@ -1,4 +1,4 @@
 MAJOR=120
 MINOR=0
 BUILD=6076
-PATCH=2
+PATCH=3