all: start v1.24.0-devel

Change-Id: I266e227245948372355c9ca1276d328a0d031cb0
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/235300
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/internal/version/version.go b/internal/version/version.go
index 6b3001c..e0db780 100644
--- a/internal/version/version.go
+++ b/internal/version/version.go
@@ -54,7 +54,7 @@
 	Major      = 1
 	Minor      = 24
 	Patch      = 0
-	PreRelease = ""
+	PreRelease = "devel"
 )
 
 // String formats the version string for this module in semver format.