Update action versions

Author: pdimens

.github/workflows/downstream.yml

@@ -7,26 +7,25 @@ on:
 jobs:
   test:
     name: ${{ matrix.package.repo }}
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     env:
       GROUP: ${{ matrix.package.group }}
     strategy:
       fail-fast: false
       matrix:
         julia-version: [1]
-        os: [ubuntu-latest]
         package:
           - {user: BioJulia, repo: PopGen.jl, group: downstream}
           - {user: pdimens, repo: PopGenSims.jl, group: downstream}
     steps:
-      - uses: actions/checkout@v4
-      - uses: julia-actions/setup-julia@v2
+      - uses: actions/checkout@v7
+      - uses: julia-actions/setup-julia@v3
         with:
           version: ${{ matrix.julia-version }}
           arch: x64
       - uses: julia-actions/julia-buildpkg@latest
       - name: Clone Downstream
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           repository: ${{ matrix.package.user }}/${{ matrix.package.repo }}
           path: downstream