fix(windows): update the last hardcoded 1.5.3 test fixture to 1.5.4

windows/tests/injector-window-readiness.test.mjs imports the real
verifySession from scripts/injector.mjs, which compares against the
real SKIN_VERSION constant -- so the mock window state's version
field has to track it too. CI caught this (Static checks and both
Windows jobs failed on this exact assertion); missed it locally
because I only grepped for skinVersion/SKIN_VERSION identifiers, not
for what the test's version field was actually compared against.
Repo-wide grep for 1.5.3 outside changelogs is now empty.

Author: Fei-Away

windows/tests/injector-window-readiness.test.mjs

@@ -83,7 +83,7 @@ function makeDomFixture({
   };
   const window = {
     __CODEX_DREAM_SKIN_STATE__: {
-      version: "1.5.3",
+      version: "1.5.4",
       themeId: "fixture-theme",
       revision: "fixture-revision",
       styleMode: "style",