chore: bump channels plugin version

Author: collins-w

examples/channels-plugin-example/channel/package-lock.json

@@ -13,7 +13,7 @@
   "author": "",
   "license": "",
   "dependencies": {
-    "@openzeppelin/relayer-plugin-channels": "^0.19.0",
+    "@openzeppelin/relayer-plugin-channels": "^0.20.0",
     "@openzeppelin/relayer-sdk": "^1.10.0"
   },
   "devDependencies": {

examples/channels-plugin-example/channel/package.json

@@ -14,7 +14,7 @@
   "author": "",
   "license": "",
   "dependencies": {
-    "@openzeppelin/relayer-plugin-channels": "^0.19.0",
+    "@openzeppelin/relayer-plugin-channels": "^0.20.0",
     "@openzeppelin/relayer-sdk": "^1.10.0"
   },
   "devDependencies": {