feat: remove OverrideSecurityTransports

This was never included in a release, and has been replaced by a flexible
transport prioritization system.

experiments.go

@@ -8,11 +8,4 @@ type Experiments struct {
 	Libp2pStreamMounting bool
 	P2pHttpProxy         bool
 	StrategicProviding   bool
-
-	// OverrideSecurityTransports overrides the set of available security
-	// transports when non-empty. This option should eventually migrate some
-	// place more stable.
-	//
-	// Default: ["tls", "secio", "noise"].
-	OverrideSecurityTransports []string `json:",omitempty"`
 }