webdriver: Keep constellation alive and Open new top-level browsing context with new session request when none is open (#37410)

Keep Constellation alive even when all browsing context closed in
WebDriver mode. In this case, when creating a new session, we would open
a new top-level browsing context.

Fixes: #37408
Testing: `./mach test-wpt -r
.\tests\wpt\tests\webdriver\tests\classic\close_window\close.py
--product servodriver`

---------

Signed-off-by: Euclid Ye <yezhizhenjiakang@gmail.com>
Signed-off-by: Euclid Ye <euclid.ye@huawei.com>

tests/wpt/meta/webdriver/tests/classic/accept_alert/accept.py.ini

@@ -12,7 +12,7 @@
     expected: FAIL
 
   [test_accept_prompt]
-    expected: ERROR
+    expected: FAIL
 
   [test_accept_in_popup_window]
     expected: FAIL

tests/wpt/meta/webdriver/tests/classic/close_window/close.py.ini

@@ -1,6 +1,3 @@
 [close.py]
   [test_close_last_browsing_context]
     expected: FAIL
-
-  [test_element_usage_after_closing_browsing_context]
-    expected: ERROR

tests/wpt/meta/webdriver/tests/classic/dismiss_alert/dismiss.py.ini

@@ -2,12 +2,6 @@
   [test_no_top_browsing_context]
     expected: ERROR
 
-  [test_no_browsing_context]
-    expected: ERROR
-
-  [test_dismiss_alert]
-    expected: FAIL
-
   [test_dismiss_confirm]
     expected: FAIL
 

tests/wpt/meta/webdriver/tests/classic/element_send_keys/file_upload.py.ini

@@ -8,11 +8,8 @@
   [test_single_file_appends_with_multiple_attribute]
     expected: FAIL
 
-  [test_focused]
-    expected: ERROR
-
   [test_strict_hidden]
-    expected: ERROR
+    expected: FAIL
 
   [test_strict_display_none]
-    expected: ERROR
+    expected: FAIL