MDL-82373 behat: Stop killing the entire Behat run on driver error

If there's a driver error, for example from a step taking too long, then
this kills the entire Behat run and we have to start from scratch.

This change instead throws away the original connection and starts a new
one to try and continue the test.

lib/behat/extension/Moodle/BehatExtension/Driver/WebDriver.php

@@ -16,6 +16,7 @@
 
 namespace Moodle\BehatExtension\Driver;
 
+use Behat\Mink\Exception\DriverException;
 use OAndreyev\Mink\Driver\WebDriver as UpstreamDriver;
 
 // phpcs:disable moodle.NamingConventions.ValidFunctionName.LowercaseMethod
@@ -79,4 +80,14 @@ class WebDriver extends UpstreamDriver {
     public function post_key($key, $xpath) {
         throw new \Exception('No longer used - please use keyDown and keyUp');
     }
+
+    #[\Override]
+    public function stop(): void {
+        try {
+            parent::stop();
+        } catch (DriverException $e) {
+            error_log($e->getMessage());
+            $this->webDriver = null;
+        }
+    }
 }