Simple file redirection should be enough here with the added advantage
of better portability.

Here-string syntax <<< is not compatible with ash/dash shells, for better portability:

  - get rid of the loop and here-string to keep variable in scope for update
  - use command substitution to record `yp` output
  - use more precise yq expression to extract plugin references

Explanation of the new yq expression:

  - `.plugins[]`: select elements of the `plugins` sequence (scalar or sequence)
  - `select(kind == "scalar")`: return scalar values (plugin without config)
  - `//`: else, when not a scalar, assume this is a sequence
  - `.[0]`: the first element of the sequence should be the plugin reference

Improve shell portability for plugin installation

Closes #56

See merge request !82

## [4.2.1](4.2.0...4.2.1) (2026-04-14)

### Bug Fixes

* replace here-string syntax with redirection ([4e2da70b](4e2da70b))
* simplify release config file parsing ([c0ba3610](c0ba3610))