Fix not being able to follow hashtags on akkoma

Closes #408

Packages/InstanceFeatures/Sources/InstanceFeatures/InstanceFeatures.swift

@@ -96,7 +96,13 @@ public class InstanceFeatures: ObservableObject {
     }
     
     public var canFollowHashtags: Bool {
-        hasMastodonVersion(4, 0, 0)
+        if case .mastodon(_, let version) = instanceType {
+            return version >= Version(4, 0, 0)
+        } else if case .pleroma(.akkoma(let version)) = instanceType {
+            return version >= Version(3, 4, 0)
+        } else {
+            return false
+        }
     }
     
     public var filtersV2: Bool {