set julia-cache action to v2 (#30)

Author: oameye

README.md

@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: julia-actions/cache@v1
+      - uses: julia-actions/cache@v2
       - name: Install JuliaFormatter and format
         run: |
           julia  -e 'import Pkg; Pkg.add("JuliaFormatter")'