fix: ignore external urls from coverage (#1955)

Author: edoardocavazza

.changeset/cold-avocados-greet.md

@@ -0,0 +1,6 @@
+---
+"@web/test-runner-coverage-v8": patch
+"@web/test-runner": patch
+---
+
+Ignore external urls from coverage

packages/test-runner-coverage-v8/src/index.ts

@@ -50,6 +50,9 @@ export async function v8ToIstanbul(
     if (
       // ignore non-http protocols (for exmaple webpack://)
       url.protocol.startsWith('http') &&
+      // ignore external urls
+      url.hostname === config.hostname &&
+      url.port === `${config.port}` &&
       // ignore non-files
       !!extname(path) &&
       // ignore virtual files