Bump actions/checkout from 2 to 3 (#335)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -23,7 +23,7 @@ jobs:
         os: ["ubuntu-latest"]
         python-version: ["3.7", "3.8", "3.9"]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: conda-incubator/setup-miniconda@v2
         with:
           channels: conda-forge
@@ -56,7 +56,7 @@ jobs:
     name: no-optional-deps
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: conda-incubator/setup-miniconda@v2
         with:
           channels: conda-forge
@@ -79,7 +79,7 @@ jobs:
     name: upstream-dev
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: conda-incubator/setup-miniconda@v2
         with:
           channels: conda-forge

.github/workflows/pypi.yaml

@@ -8,7 +8,7 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v3
       - name: Set up Python
         uses: actions/setup-python@v3
         with: