fix: disable WebUIReloadButton experiment in Chrome launcher (#3438)

Ports upstream Puppeteer PR #14925. The WebUIReloadButton experiment
creates additional targets (browser_ui type and a corresponding tab
target) that cause test failures in TargetManager tests.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: kblok

lib/PuppeteerSharp/ChromeLauncher.cs

@@ -63,6 +63,7 @@ internal static string[] GetDefaultArgs(LaunchOptions options)
                 "AcceptCHFrame",
                 "MediaRouter",
                 "OptimizationHints",
+                "WebUIReloadButton",
                 "IPH_ReadingModePageActionLabel",
                 "ReadAnythingOmniboxChip",
                 "ProcessPerSiteUpToMainFrameThreshold",