Framebuffers: Forget the depth shift tracking with the framebuffers

DestroyAllFBOs (on a savestate load) kept depthShiftedFor_ and
lastRenderAddress_, so a new framebuffer at the same address as the old
one skipped the depth shift for a frame.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

GPU/Common/FramebufferManagerCommon.cpp

@@ -3132,6 +3132,9 @@ void FramebufferManagerCommon::NotifyConfigChanged() {
 void FramebufferManagerCommon::DestroyAllFBOs() {
 	DiscardFramebufferCopy();
 	currentRenderVfb_ = nullptr;
+	// Or a new framebuffer at the same address would skip its depth shift.
+	depthShiftedFor_ = 0;
+	lastRenderAddress_ = 0;
 	displayFramebuf_ = nullptr;
 	prevDisplayFramebuf_ = nullptr;
 	prevPrevDisplayFramebuf_ = nullptr;