Hello,
Please attempt to acquire the azure-core.dll either from the internet or a functional PC with the same operating system. Once obtained, open your Windows username folder, proceed to AppData - Local - Microsoft - Teams - Current, and paste the copied DLL file into the folder.
Alternatively, you may consider uninstalling and reinstalling the Microsoft Teams app.
Download Microsoft Teams Desktop and Mobile Apps | Microsoft Teams [4b91-98b4-9c1-3ac0]