Bump actions/setup-python from 2 to 4 (#1686)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 2 to 4.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v2...v4)

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

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: BobDotCom <71356958+BobDotCom@users.noreply.github.com>

.github/workflows/bandit.yml

@@ -6,6 +6,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3.1.0
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v4
       - run: pip install bandit
       - run: bandit --recursive  --skip B101,B104,B105,B110,B307,B311,B404,B603,B607 .

.github/workflows/codespell.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3.1.0
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v4
       - run: pip install codespell==2.1.0
       - run:
           codespell --ignore-words-list="groupt,nd,ot,ro,falsy,BU" \

.github/workflows/docs.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3.1.0
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies

.github/workflows/mypy.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3.1.0
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v4
       - run: pip install -r requirements-dev.txt
       - run: mkdir --parents --verbose .mypy_cache
       - run: mypy --non-interactive discord/

.github/workflows/python-app.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3.1.0
       - name: Set up Python 3.10
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies