Incrementing VERSION to 106.0.5249.91

Change-Id: I2f30593ff98abc1b598b949152fa983b3117c08b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3926183
Bot-Commit: Chrome Release Bot (LUCI) <chrome-official-brancher@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/5249@{#707}
Cr-Branched-From: 4f7bea5-refs/heads/main@{#1036826}

chrome/VERSION

@@ -1,4 +1,4 @@
 MAJOR=106
 MINOR=0
 BUILD=5249
-PATCH=90
+PATCH=91