[WTR/Playwright] "Error: page.goto:" messages void passed tests in Firefox

[Westbrook]

This code seems to get called twice: https://github.com/modernweb-dev/web/blob/245123e1b92fe0d468fc7ae1e25663f52e775bea/packages/test-runner-playwright/src/PlaywrightLauncherPage.ts#L46-L57 I'm working on why, but when it does the second navigation to about:blank fails the first navigation and passed tests are voided.

The dumbest, fastest approach seems to be to add a gate, like so (copied from JS output):

stoppingSession = false;
    async stopSession() {
        const testCoverage = this.nativeInstrumentationEnabledOnPage
            ? await this.collectTestCoverage(this.config, this.testFiles)
            : undefined;
        if (!this.stoppingSession) {
            this.stoppingSession = true;
            return { testCoverage };
        }
        // navigate to an empty page to kill any running code on the page, stopping timers and
        // breaking a potential endless reload loop
        await this.playwrightPage.goto('about:blank');
        await this.playwrightContext.close();
        return { testCoverage };
    }

Further up the line, we could change the isActive call to confirm that URL isn't about:blank, like (maybe, I've not tested this):

isActive(sessionId: string) {
    return this.activePages.has(sessionId) && this.activePages.get(sessionId).url !== 'about:blank';
}

OR, maybe we could do something about holding better state all the way up at the TestScheduler.ts level.

Thoughts?