Update format_pr.yml

Author: Avik Pal

.github/workflows/format_pr.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        julia-version: '1.6'
+        julia-version: [1.8]
         julia-arch: [x86]
         os: [ubuntu-latest]
     steps: