Swift: bump actions/setup-python from 3 to 4

Also fixes python version with a `.pythonversion` file.

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 3 to 4.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v3...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>

.github/workflows/swift-autobuilder.yml

@@ -16,7 +16,9 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version-file: 'swift/.python-version'
       - name: Build the Xcode autobuilder
         run: |
           bazel build //swift/xcode-autobuilder

.github/workflows/swift-codegen.yml

@@ -10,6 +10,9 @@ on:
       - .github/actions/fetch-codeql/action.yml
     branches:
       - main
+defaults:
+  run:
+    working-directory: swift
 
 jobs:
   codegen:
@@ -18,7 +21,9 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/fetch-codeql
       - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version-file: 'swift/.python-version'
       - uses: pre-commit/action@v3.0.0
         name: Check that python code is properly formatted
         with:

.github/workflows/swift-integration-tests.yml

@@ -28,7 +28,9 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/fetch-codeql
       - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version-file: 'swift/.python-version'
       - name: Build Swift extractor
         run: |
           bazel run //swift:create-extractor-pack

.github/workflows/swift-qltest.yml

@@ -33,6 +33,9 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/fetch-codeql
       - uses: bazelbuild/setup-bazelisk@v2
+      - uses: actions/setup-python@v4
+        with:
+          python-version-file: 'swift/.python-version'
       - name: Build Swift extractor
         run: |
           bazel run //swift:create-extractor-pack

swift/.python-version

@@ -0,0 +1 @@
+3.8.14

swift/integration-tests/runner.py

@@ -16,8 +16,7 @@ import argparse
 import shutil
 import platform
 
-this_dir = pathlib.Path(__file__).parent
-
+this_dir = pathlib.Path(__file__).parent.resolve()
 
 def options():
     p = argparse.ArgumentParser()