Replace futures::executor::block_on with tokio::block_in_place

tests-pl/issue-http_open-hanging.pl

@@ -0,0 +1,23 @@
+:- module(http_open_hanging, [submit_request/0]).
+
+:- use_module(library(charsio)).
+:- use_module(library(http/http_open)).
+
+send_request :-
+    Options = [
+        method('get'),
+        status_code(StatusCode),
+        request_headers([]),
+        headers(_)
+    ],
+    http_open("https://scryer.pl", _Stream, Options),
+    write_term('received response with status code':StatusCode, []), nl.
+
+main :-
+    send_request,
+    send_request,
+    send_request,
+    send_request,
+    send_request.
+
+:- initialization(main).