Fix steep warnings

Author: y9v

lib/datadog/tracing/contrib/rack/route_inference.rb

@@ -28,7 +28,7 @@ def infer(path)
             segments = path.delete_prefix('/').split('/', MAX_NUMBER_OF_SEGMENTS + 1).first(MAX_NUMBER_OF_SEGMENTS)
 
             segments.map! do |segment|
-              next if segment.empty?
+              next if segment.empty? # steep:ignore
 
               case segment
               when INT_PARAM_REGEX then '{param:int}'

sig/datadog/tracing/contrib/rack/route_inference.rbs

@@ -13,9 +13,9 @@ module Datadog
 
           DATADOG_INFERRED_ROUTE_ENV_KEY: ::String
 
-          def self.read_or_infer: (Hash[::String, untyped] request_env) -> ::String?
+          def self?.read_or_infer: (Hash[::String, untyped] request_env) -> ::String?
 
-          def self.infer: (::String path) -> ::String?
+          def self?.infer: (::String path) -> ::String?
         end
       end
     end