[19208] Improve script portability

[JLBuenoLopez]

Description

In order to improve script portability, instead of setting the absolute path to the interpreter, this PR modifies the shebang to make use of /usr/bin/env program. This can have its own portability issues, though it seems that most systems agrees with this convention.

This PR fixes #3734.

@Mergifyio backport 2.11.x 2.10.x 2.6.x

Contributor Checklist

• Commit messages follow the project guidelines.
• [N/A] The code follows the style guidelines of this project.
• [N/A] Tests that thoroughly check the new feature have been added/Regression tests checking the bug and its fix have been added; the added tests pass locally
• [N/A] Any new/modified methods have been properly documented using Doxygen.
• [N/A] Changes are ABI compatible.
• [N/A] Changes are API compatible.
• [N/A] New feature has been added to the versions.md file (if applicable).
• [N/A] New feature has been documented/Current behavior is correctly described in the documentation.
• Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• Check contributor checklist is correct.
• Check CI results: changes do not issue any warning.
• Check CI results: failing tests are unrelated with the changes.