Bump julia-actions/setup-julia from 1 to 2

Bumps [julia-actions/setup-julia](https://github.com/julia-actions/setup-julia) from 1 to 2.
- [Release notes](https://github.com/julia-actions/setup-julia/releases)
- [Changelog](https://github.com/julia-actions/setup-julia/blob/master/devdocs/making_a_new_release.md)
- [Commits](julia-actions/setup-julia@v1...v2)

---
updated-dependencies:
- dependency-name: julia-actions/setup-julia
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/CI.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: julia-actions/setup-julia@v1
+      - uses: julia-actions/setup-julia@v2
         with:
           version: 1
       - uses: actions/cache@v1

.github/workflows/CompatHelper.yml

@@ -15,7 +15,7 @@ jobs:
         run: which julia
         continue-on-error: true
       - name: Install Julia, but only if it is not already available in the PATH
-        uses: julia-actions/setup-julia@v1
+        uses: julia-actions/setup-julia@v2
         with:
           version: '1'
           arch: ${{ runner.arch }}