fix: parse json to extract terraform version

[ferrarimarco]

Request JSON output when getting the Terraform version to build the versions.txt file. When using terraform version, and piping the output to head (to get the first line) and then to awk (to get the version string), there's a race condition that might cause head to close the pipe before Terraform flushed its entire output to the pipe, resulting in a 141 error (141 -128 = 13 -> SIGPIPE).

This change is expected to make the CI workflow more stable.

Readiness checklist

In order to have this pull request merged, complete the following tasks.

Pull request author tasks

• I checked that all workflows return a success.
• I included all the needed documentation for this change.
• I provided the necessary tests.
• I squashed all the commits into a single commit.
• I followed the
  Conventional Commit v1.0.0 spec.
• I wrote the necessary upgrade instructions in the
  upgrade guide.
• If this pull request is about and existing issue, I added the
  Fix #ISSUE_NUMBER or Close #ISSUE_NUMBER text to the description of
  the pull request.

Super-linter maintainer tasks

• Label as breaking if this change breaks compatibility with the previous
  released version.
• Label as either: automation, bug, documentation, enhancement,
  infrastructure.
• Add the pull request to a milestone, eventually creating one, that matches
  with the version that release-please proposes in the
  preview-release-notes CI job.