fix(headers): support HTTP2 pseudo-headers

which begin with `:` e.g. `:authority`, `:method`, etc.

Author: pcattori

.changeset/wise-dogs-clean.md

@@ -0,0 +1,5 @@
+---
+"@remix-run/web-fetch": patch
+---
+
+Support HTTP2 pseudo-headers like `:authority`, `:method`, etc.

packages/fetch/src/headers.js

@@ -15,7 +15,7 @@ const validators = (http)
  * @param {string} name
  */
 const validateHeaderName = name => {
-	if (!/^[\^`\-\w!#$%&'*+.|~]+$/.test(name)) {
+	if (!/^[\^`\-\w!#$%&'*+.|~:]+$/.test(name)) {
 		const err = new TypeError(`Header name must be a valid HTTP token [${name}]`);
 		Object.defineProperty(err, 'code', {value: 'ERR_INVALID_HTTP_TOKEN'});
 		throw err;