chore: remove unneeded blocks pubsub implementation

go.mod

@@ -3,7 +3,6 @@ module github.com/ipfs/bifrost-gateway
 go 1.19
 
 require (
-	github.com/cskr/pubsub v1.0.2
 	github.com/filecoin-saturn/caboose v0.0.3
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/hashicorp/golang-lru/v2 v2.0.1
@@ -20,7 +19,6 @@ require (
 	github.com/libp2p/go-libp2p-routing-helpers v0.7.0
 	github.com/mitchellh/go-server-timing v1.0.1
 	github.com/multiformats/go-multicodec v0.9.0
-	github.com/multiformats/go-multihash v0.2.3
 	github.com/prometheus/client_golang v1.15.1
 	github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417
 	github.com/spf13/cobra v1.6.1
@@ -97,6 +95,7 @@ require (
 	github.com/multiformats/go-multiaddr v0.8.0 // indirect
 	github.com/multiformats/go-multiaddr-dns v0.3.1 // indirect
 	github.com/multiformats/go-multibase v0.2.0 // indirect
+	github.com/multiformats/go-multihash v0.2.3 // indirect
 	github.com/multiformats/go-multistream v0.4.1 // indirect
 	github.com/multiformats/go-varint v0.0.7 // indirect
 	github.com/opencontainers/runtime-spec v1.0.3-0.20211123151946-c2389c3cb60a // indirect

go.sum

@@ -68,7 +68,6 @@ github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46t
 github.com/crackcomm/go-gitignore v0.0.0-20170627025303-887ab5e44cc3 h1:HVTnpeuvF6Owjd5mniCL8DEXo7uYXdQEmOP4FJbV5tg=
 github.com/crackcomm/go-gitignore v0.0.0-20170627025303-887ab5e44cc3/go.mod h1:p1d6YEZWvFzEh4KLyvBcVSnrfNDDvK2zfK/4x2v/4pE=
 github.com/cskr/pubsub v1.0.2 h1:vlOzMhl6PFn60gRlTQQsIfVwaPB/B/8MziK8FhEPt/0=
-github.com/cskr/pubsub v1.0.2/go.mod h1:/8MzYXk/NJAz782G8RPkFzXTZVu63VotefPnR9TIRis=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=