chore(deps): bump the actions group across 1 directory with 5 updates (#5941)

* chore(deps): bump the actions group across 1 directory with 5 updates

Bumps the actions group with 5 updates in the / directory:

| Package | From | To |
| --- | --- | --- |
| [actions/checkout](https://github.com/actions/checkout) | `1` | `6` |
| [actions/cache](https://github.com/actions/cache) | `4` | `5` |
| [actions/upload-artifact](https://github.com/actions/upload-artifact) | `5` | `6` |
| [actions/download-artifact](https://github.com/actions/download-artifact) | `6` | `7` |
| [scientific-python/upload-nightly-action](https://github.com/scientific-python/upload-nightly-action) | `0.6.2` | `0.6.3` |



Updates `actions/checkout` from 1 to 6
- [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/v1...v6)

Updates `actions/cache` from 4 to 5
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v4...v5)

Updates `actions/upload-artifact` from 5 to 6
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v5...v6)

Updates `actions/download-artifact` from 6 to 7
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v6...v7)

Updates `scientific-python/upload-nightly-action` from 0.6.2 to 0.6.3
- [Release notes](https://github.com/scientific-python/upload-nightly-action/releases)
- [Commits](https://github.com/scientific-python/upload-nightly-action/compare/b36e8c0c10dbcfd2e05bf95f17ef8c14fd708dbf...5748273c71e2d8d3a61f3a11a16421c8954f9ecf)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/download-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: scientific-python/upload-nightly-action
  dependency-version: 0.6.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: actions
...

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

* Reset install-classic actions/checkout to @v1

* Pin actions/checkout@v1 to SHA, switch dependabot to monthly

Pin the i386/debian container checkout to SHA to prevent dependabot
from updating it (v1 is required for that container). Remove the
non-working ignore block and change schedule from weekly to monthly.

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>