perf(session): improve page management and speed up execution

Close pages immediately after tasks finish to reduce resource usage and
improve overall performance. Update corresponding test files to reflect
the new page lifecycle management.

tests/fetchers/test_pages.py

@@ -24,10 +24,6 @@ class TestPageInfo:
         assert page_info.state == "busy"
         assert page_info.url == "https://example.com"
 
-        page_info.mark_finished()
-        assert page_info.state == "finished"
-        assert page_info.url == ""
-
         page_info.mark_error()
         assert page_info.state == "error"
 
@@ -88,21 +84,7 @@ class TestPagePool:
         with pytest.raises(RuntimeError):
             pool.add_page(Mock())
 
-    def test_get_ready_page(self):
-        """Test getting ready page"""
-        pool = PagePool(max_pages=3)
 
-        # Add pages
-        page1 = pool.add_page(Mock())
-        page2 = pool.add_page(Mock())
-
-        # Mark them as finished
-        page1.mark_finished()
-        page2.mark_finished()
-
-        # test
-        pool.close_all_finished_pages()
-        assert pool.pages_count == 0
 
     def test_cleanup_error_pages(self):
         """Test cleaning up error pages"""