README: update badges (#790)

Author: danirabbit

README.md

@@ -16,8 +16,8 @@
 </div>
 
 <p align="center">
-  <img src="https://github.com/elementary/os/actions/workflows/stable-8.0.yml/badge.svg" alt="Stable 8.0">
-  <img src="https://github.com/elementary/os/actions/workflows/daily-8.0.yml/badge.svg" alt="Daily 8.0">
+  <img src="https://github.com/elementary/os/actions/workflows/stable-8.1.yml/badge.svg" alt="Stable 8.1">
+  <img src="https://github.com/elementary/os/actions/workflows/daily-8.1.yml/badge.svg" alt="Daily 8.1">
 </p>
 
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