EESSI bot v0.9.0

This is a minor release of the EESSI build-and-deploy bot.

Note! Though it is a minor release it includes breaking changes of the bot
configuration and the user interface for triggering build jobs. For details
see below and documentation at https://www.eessi.io/docs/bot/#building

Bug fixes:

• revised and updated app.cfg.example and README.md (#325)

Improvements:

• add support for cloning target repository via ssh (#300)
• major refactoring of the definition of build targets and breaking change in
  bot configuration and of the user interface to trigger builds (#312, #329, #331, #337)
  • arch_target_map is replaced by node_type_map which provides a more
    comprehensive/flexible approach to define architectures that are available
    for build jobs; for details, see https://github.com/EESSI/eessi-bot-software-layer?tab=readme-ov-file#architecturetargets-section
  • the repo_target_map setting is removed because the information is now
    included in the node_type_map setting
  • the initial_comment setting in the [submitted_job_comments] section of the bot configuration
    has been replaced with separate settings: new_job_instance_repo, build_on_arch, build_for_arch, jobdir;
    for details, see https://github.com/EESSI/eessi-bot-software-layer/blob/develop/README.md#submitted_job_comments-section
    and the example bot configuration app.cfg.example;
  • bot:build filters architecture: and accel: are replaced by on: and
    for: (for details see documentation at https://www.eessi.io/docs/bot/#building)
• add CI to build and publish smee-client container image (#321, #322)
• make space before bot command optional (#324)
• support template values in the scontrol command (#327, #335)
• support additional parameter (last_build) for bot:status command (#334)

Changes to 'app.cfg' settings (see README.md and app.cfg.example for details):

• REMOVED (required) 'arch_target_map' in section '[architecturetargets]', replaced by
  'node_type_map'
• REMOVED (required) 'repo_target_map' in section '[repo_targets]', replaced by
  'node_type_map'
• NEW (required) 'node_type_map' in section '[architecturetargets]'
• NEW (optional) 'clone_git_repo_via' in section '[buildenv]'
• NEW (required) 'pr_diff_failure' in section '[download_pr_comments]'
• NEW (required) 'pr_diff_tip' in section '[download_pr_comments]'