adding Request#can_buffer?

abstracts some logic around whether a request has request body bytes to buffer

lib/httpx/connection/http1.rb

@@ -93,7 +93,7 @@ module HTTPX
       concurrent_requests_limit = [@max_concurrent_requests, requests_limit].min
       @requests.each_with_index do |request, idx|
         break if idx >= concurrent_requests_limit
-        next if request.state == :done
+        next unless request.can_buffer?
 
         handle(request)
       end

lib/httpx/connection/http2.rb

@@ -124,7 +124,7 @@ module HTTPX
 
     def consume
       @streams.each do |request, stream|
-        next if request.state == :done
+        next unless request.can_buffer?
 
         handle(request, stream)
       end

lib/httpx/request.rb

@@ -155,6 +155,10 @@ module HTTPX
       :w
     end
 
+    def can_buffer?
+      @state != :done
+    end
+
     # merges +h+ into the instance of HTTPX::Headers of the request.
     def merge_headers(h)
       @headers = @headers.merge(h)

sig/request.rbs

@@ -39,6 +39,8 @@ module HTTPX
 
     def interests: () -> (:r | :w)
 
+    def can_buffer? : () -> bool
+
     def merge_headers: (_Each[[String, headers_value]]) -> void
 
     def scheme: () -> String