feat(config): Add support for v1.1 protocol of secrets exec backend (#23655)

* feat(config): Add support for v1.1 of datadog secrets manager

* Update docs generator to generate unconstrained types

- This is necessary as the secrets exec config now contains a member of
type `Value`

* Introduce new unit tests for the exec backend

* Add changelog file

* Stray line to format

* Rename mock exec script and make it executable

- That way its implementation can change without modifying the
  executables call site in the code.

* Update src/secrets/exec.rs

* Install python 3.10 on windows CI runs

* Invoke python mock exec program via the python command

- Shebang invocation at top of script not working on windows builds
where python is installed and located at the path

* Revert "Install python 3.10 on windows CI runs"

This reverts commit c4f9570e6d51714ff01601401f7a50304815bba2.

* Reapply "Install python 3.10 on windows CI runs"

This reverts commit fb5120159928dbd90b5070df5aa132b7006e1850.

---------

Co-authored-by: Pavlos Rontidis <pavlos.rontidis@gmail.com>
Co-authored-by: Thomas <thomasqueirozb@gmail.com>