all: release v1.36.9

Change-Id: I815c693cf5fe6265193a522335ab81219065d613
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/701876
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Florian Zenker <floriank@google.com>

internal/version/version.go

diff --git a/internal/version/version.go b/internal/version/version.go
index f6b3cdc..31e79a6 100644
--- a/internal/version/version.go
+++ b/internal/version/version.go
@@ -52,8 +52,8 @@
 const (
 	Major      = 1
 	Minor      = 36
-	Patch      = 8
-	PreRelease = "devel"
+	Patch      = 9
+	PreRelease = ""
 )
 
 // String formats the version string for this module in semver format.