Unable to Delete imageres.dll.mun File

I recently deleted some content and inadvertently reverted my Windows 11 icons back to the Windows 10 ones. I had been using the Windows 11 icons for quite some time, so the change surprised me. After a Windows update, I found myself unable to delete a specific file because it required permission from TrustedInstaller.exe. While I believe I am the owner of TrustedInstaller, I am unsure why this permission issue has arisen. Previously, I could easily delete this file, but now I'm facing obstacles.