Have to invalidate "lastBoundTexture" when binding framebuffers as texture.

Fixes parts of #13431 for D3D11 at least.

Will probably soon get rid of this concept, it's only useful in D3D9/11 and
those are probably not gonna lose much perf if we remove this minor
state caching.

GPU/Common/TextureCacheCommon.cpp

@@ -1588,6 +1588,7 @@ void TextureCacheCommon::ApplyTexture() {
 		// Maybe we bound a framebuffer?
 		if (nextFramebufferTexture_) {
 			bool depth = Memory::IsDepthTexVRAMAddress(gstate.getTextureAddress(0));
+			InvalidateLastTexture();
 			ApplyTextureFramebuffer(nextFramebufferTexture_, gstate.getTextureFormat(), depth ? NOTIFY_FB_DEPTH : NOTIFY_FB_COLOR);
 			nextFramebufferTexture_ = nullptr;
 		}

GPU/D3D11/TextureCacheD3D11.cpp

@@ -145,6 +145,7 @@ void TextureCacheD3D11::ReleaseTexture(TexCacheEntry *entry, bool delete_them) {
 void TextureCacheD3D11::ForgetLastTexture() {
 	InvalidateLastTexture();
 	gstate_c.Dirty(DIRTY_TEXTURE_PARAMS);
+
 	ID3D11ShaderResourceView *nullTex[2]{};
 	context_->PSSetShaderResources(0, 2, nullTex);
 }