housekeeping: Fix the release tag (#106)

Author: glennawatson

version.json

@@ -1,9 +1,7 @@
 {
   "version": "3.3",
   "publicReleaseRefSpec": [
-    "^refs/heads/master$", // we release out of master
-    "^refs/heads/develop$", // we release out of develop
-    "^refs/heads/rel/\\d+\\.\\d+\\.\\d+" // we also release branches starting with rel/N.N.N
+    "^refs/heads/main$", // we release out of master
   ],
   "nugetPackageVersion":{
     "semVer": 2