refactor: change URL max length to 8000

The previous limit of 2000 characters was a bit too low in certain cases.

From https://www.rfc-editor.org/rfc/rfc9110#section-4.1-5

> It is RECOMMENDED that all senders and recipients support, at a minimum, URIs with lengths of 8000 octets in protocol elements.

Related: #715

See also: 707597d

lib/contrib/parseuri.ts

@@ -24,7 +24,7 @@ const parts = [
 ];
 
 export function parse(str: string) {
-    if (str.length > 2000) {
+    if (str.length > 8000) {
         throw "URI too long";
     }
 

test/parseuri.js

@@ -66,6 +66,6 @@ describe("parseuri", function () {
     expect(relativeWithQuery.path).to.be("/foo");
     expect(relativeWithQuery.query).to.be("bar=@example.com");
 
-    expect(() => parseuri(repeat("a", 2001))).to.throwError("URI too long");
+    expect(() => parseuri(repeat("a", 8001))).to.throwError("URI too long");
   });
 });