CI: set Go version to 1.20.5

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

.github/workflows/release.yml

@@ -5,7 +5,7 @@ on:
     tags: 'v*'
 
 env:
-  GO_VERSION: 1.20.4
+  GO_VERSION: 1.20.5
 
 jobs:
   prepare-sources-with-deps: