build: add atari 8mb to nightly build (#1021)

Author: mozzwald

.github/workflows/nightly.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: "ubuntu-latest"
     strategy:
       matrix:
-        target-platform: [ATARI, ADAM, APPLE, IEC-LOLIN-D32, IEC-NUGGET, COCO, MASTERIES-REVAB, MASTERIES-REVA-SPIFIX, RS232]
+        target-platform: [ATARI, ATARI-8mb, ADAM, APPLE, IEC-LOLIN-D32, IEC-NUGGET, COCO, MASTERIES-REVAB, MASTERIES-REVA-SPIFIX, RS232]
 
     steps:
     - name: Checkout Source