Incrementing VERSION to 122.0.6256.7

Change-Id: I6badc3ff8a435692eefdd0e54eff8ba0842bfe12
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5214246
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/6256@{#12}
Cr-Branched-From: 4cc21c9-refs/heads/main@{#1248731}

chrome/VERSION

@@ -1,4 +1,4 @@
 MAJOR=122
 MINOR=0
 BUILD=6256
-PATCH=6
+PATCH=7