Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v3...v4

)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/autopush.yml

@@ -9,7 +9,7 @@ jobs:
         name: Automatic push to gitlab.tiker.net
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   run: |
                 mkdir ~/.ssh && echo -e "Host gitlab.tiker.net\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
                 eval $(ssh-agent) && echo "$GITLAB_AUTOPUSH_KEY" | ssh-add -

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
         name: Flake8
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -
             uses: actions/setup-python@v4
             with:
@@ -27,7 +27,7 @@ jobs:
         name: Pylint
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: "Main Script"
             run: |
                 USE_CONDA_BUILD=1
@@ -41,7 +41,7 @@ jobs:
         name: Documentation
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: "Main Script"
             run: |
                 CONDA_ENVIRONMENT=.test-conda-env-py3.yml
@@ -54,7 +54,7 @@ jobs:
         name: Conda Pytest
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: "Main Script"
             run: |
                 grep -v symengine .test-conda-env-py3.yml > .test-conda-env.yml
@@ -66,7 +66,7 @@ jobs:
         name: Conda Pytest Symengine
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: "Main Script"
             run: |
                 curl -L -O https://gitlab.tiker.net/inducer/ci-support/raw/main/build-and-test-py-project-within-miniconda.sh
@@ -76,7 +76,7 @@ jobs:
         name: Conda Examples
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: "Main Script"
             run: |
                 grep -v symengine .test-conda-env-py3.yml > .test-conda-env.yml
@@ -94,7 +94,7 @@ jobs:
         name: Tests for downstream project ${{ matrix.downstream_project }}
         runs-on: ubuntu-latest
         steps:
-        -   uses: actions/checkout@v3
+        -   uses: actions/checkout@v4
         -   name: "Main Script"
             env:
                 DOWNSTREAM_PROJECT: ${{ matrix.downstream_project }}