* feat(config) allow setting assume-yes in config

fixes #1212
related: STACKITCLI-327

kubectl calls stackit-cli for auth. To enable e2e tests for this ske
feature, it would be nice to save assume-yes to the config.

* fix(config) use `_` for unused params

* fix(config) add assume-yes to unset_test

* extract kubeconfig certificate validation

* simplify kubeconfig retrieval

* extract kubeconfig retrieval

* reorder imports

* Split kubeconfig retrieval and output

* replace hardcoded timeout with constant

* implement kubeconfig login --idp flow

* Add tests

* fix test failure if KUBECONFIG environment variable is set

* make retrieval of idp well known config reusable

* optionally initialize IDP_TOKEN_ENDPOINT auth field for service accounts

When activating a service account, clear a possibly stale old value. Add
a separate method to allow commands to request the initialization of the
IDP_TOKEN_ENDPOINT auth field.

* refactor token exchange into auth package

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v7...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Alexander Dahmen <alexander.dahmen@inovex.de>

relates to STACKITCLI-276

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Bumps [crazy-max/ghaction-import-gpg](https://github.com/crazy-max/ghaction-import-gpg) from 6 to 7.
- [Release notes](https://github.com/crazy-max/ghaction-import-gpg/releases)
- [Commits](crazy-max/ghaction-import-gpg@v6...v7)

---
updated-dependencies:
- dependency-name: crazy-max/ghaction-import-gpg
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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