Update version to v1.9.0

Benjamin Rewis · Benjamin Rewis · commit 35f33daefb0e · 2022-04-06T11:07:03.000-04:00
diff --git a/version/version.go b/version/version.go
@@ -7,4 +7,4 @@
 package version // import "go.mongodb.org/mongo-driver/version"
 
 // Driver is the current version of the driver.
-var Driver = "v1.9.0+prerelease"
+var Driver = "v1.9.0"
