Bump shelljs and azure-pipelines-task-lib in /tasks/buildAndReleaseTask

Bumps [shelljs](https://github.com/shelljs/shelljs) to 0.8.5 and updates ancestor dependency [azure-pipelines-task-lib](https://github.com/Microsoft/azure-pipelines-task-lib). These dependencies need to be updated together.


Updates `shelljs` from 0.3.0 to 0.8.5
- [Release notes](https://github.com/shelljs/shelljs/releases)
- [Changelog](https://github.com/shelljs/shelljs/blob/master/CHANGELOG.md)
- [Commits](shelljs/shelljs@v0.3.0...v0.8.5)

Updates `azure-pipelines-task-lib` from 2.9.3 to 4.0.0-preview
- [Release notes](https://github.com/Microsoft/azure-pipelines-task-lib/releases)
- [Commits](https://github.com/Microsoft/azure-pipelines-task-lib/commits)

---
updated-dependencies:
- dependency-name: shelljs
  dependency-type: indirect
- dependency-name: azure-pipelines-task-lib
  dependency-type: direct:production
...

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

Author: dependabot[bot]