deps: update pubsub interface (#220)

Author: achingbrain

package.json

@@ -150,7 +150,7 @@
     "@libp2p/interface-peer-id": "^2.0.0",
     "@libp2p/interface-pubsub": "^4.0.0",
     "@libp2p/logger": "^2.0.0",
-    "@libp2p/pubsub": "^6.0.0",
+    "@libp2p/pubsub": "^7.0.0",
     "protons-runtime": "^5.0.0",
     "uint8arraylist": "^2.1.1",
     "uint8arrays": "^4.0.3"