build(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

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

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

Author: dependabot[bot]

.github/workflows/dockerised-postgres.yml

@@ -48,7 +48,7 @@ jobs:
           - 5433:5432
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run test noproc fixture on docker
         uses: fizyk/actions-reuse/.github/actions/pipenv@v4.1.1
         with:

.github/workflows/oldest-postgres.yml

@@ -34,7 +34,7 @@ jobs:
       PYTHON: ${{ matrix.python-version }}
       POSTGRES: ${{ inputs.postgresql }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Pipenv on python ${{ matrix.python-version }}
         uses: fizyk/actions-reuse/.github/actions/pipenv-setup@v4.1.1
         with:

.github/workflows/single-postgres.yml

@@ -34,7 +34,7 @@ jobs:
       PYTHON: ${{ matrix.python-version }}
       POSTGRES: ${{ inputs.postgresql }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Pipenv on python ${{ matrix.python-version }}
         uses: fizyk/actions-reuse/.github/actions/pipenv-setup@v4.1.1
         with: