all: start v1.34.1-devel

Change-Id: I351d7c1945d8915904a753b8d5faf861d2e06a43
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/583436
Auto-Submit: Lasse Folger <lassefolger@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Stapelberg <stapelberg@google.com>

internal/version/version.go

@@ -53,7 +53,7 @@ const (
 	Major      = 1
 	Minor      = 34
 	Patch      = 1
-	PreRelease = ""
+	PreRelease = "devel"
 )
 
 // String formats the version string for this module in semver format.