Bump actions/setup-python from 5 to 6 (OpenAPITools#21901)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 5 to 6.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/samples-postman.yaml

@@ -20,7 +20,7 @@ jobs:
           - "3.12"
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install

.github/workflows/samples-python-client-echo-api.yaml

@@ -25,7 +25,7 @@ jobs:
           - "3.13"
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Setup node.js

.github/workflows/samples-python-fastapi-server.yaml

@@ -19,7 +19,7 @@ jobs:
           - samples/server/petstore/python-fastapi/
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.9'
       - name: Install dependencies

.github/workflows/samples-python-petstore.yaml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.13"
       - name: Install validator
@@ -45,7 +45,7 @@ jobs:
           SWAGGER_BASE_PATH: /v2
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         id: py
         with:
           python-version: ${{ matrix.python-version }}

.github/workflows/samples-python-pydantic-v1-client-echo-api.yaml

@@ -24,7 +24,7 @@ jobs:
           - "3.12"
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Setup node.js

.github/workflows/samples-python-pydantic-v1-petstore.yaml

@@ -32,7 +32,7 @@ jobs:
           SWAGGER_BASE_PATH: /v2
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         id: py
         with:
           python-version: ${{ matrix.python-version }}

.github/workflows/samples-python-server.yaml

@@ -19,7 +19,7 @@ jobs:
           - samples/server/petstore/python-aiohttp-srclayout/
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.9'
       - name: Test