Environment Variable Lifecycle

[dragonchaser]

To automatically create a changelist for environment-variables between versions we need to introduce a new field to the variable description that contains the introduction version of the variable.

Currently those descriptions look like this:

Timeout int64         `yaml:"timeout" env:"ANTIVIRUS_ICAP_TIMEOUT" desc:"Timeout for the ICAP client." deprecationVersion:"5.0" removalVersion:"6.0" deprecationInfo:"Changing the envvar type for consistency reasons." deprecationReplacement:"ANTIVIRUS_ICAP_SCAN_TIMEOUT"`

In the future it should look like this:

Timeout int64         `yaml:"timeout" env:"ANTIVIRUS_ICAP_TIMEOUT" desc:"Timeout for the ICAP client." introductionVersion:"4.0" deprecationVersion:"5.0" removalVersion:"6.0" deprecationInfo:"Changing the envvar type for consistency reasons." deprecationReplacement:"ANTIVIRUS_ICAP_SCAN_TIMEOUT"`

TODO:

• Prerequisite: Add the introductionVersion field to all existing environment variables #8434
• Write an extension to the ci that rejects PRs that contain env variables without the introductionVersion field
  implementation of the step is in Check env var annotations #8436 not added to the ci yet
• Create a tool in docs/helpers that creates a list of environment variables between to versions (those versions should be passed to the tool using cli arguments. For example envdeltahelper 4.0 5.0 should create the list of newly introduced variables between 4.0 and 5.0.
• [ ] Include this tool into the release pipeline and append the corresponding list to the changelog upon release. Needs to be run manually for now

[dragonchaser]

/cc @mmattel && @micbar

[dragonchaser]

current approach is in #8454 blocked unti #8434 is solved