all: start v1.36.1-devel

Change-Id: I7c57fd7034f1a55e25fb0e5654c0e9fcde14d4c4
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/637938
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Chressie Himpel <chressie@google.com>

internal/version/version.go

diff --git a/internal/version/version.go b/internal/version/version.go
index 3018450..e9da8c0 100644
--- a/internal/version/version.go
+++ b/internal/version/version.go
@@ -53,7 +53,7 @@
 	Major      = 1
 	Minor      = 36
 	Patch      = 1
-	PreRelease = ""
+	PreRelease = "devel"
 )
 
 // String formats the version string for this module in semver format.