update github actions

Author: lovasoa

.github/workflows/publish.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: install deps
         run: sudo apt-get install coinor-cbc coinor-libcbc-dev
       - run: cargo publish

.github/workflows/rust.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: conda-incubator/setup-miniconda@v2
         with:
           activate-environment: test