Use Issues & PR templates from the organization repo

[MathieuLamiot]

Description

PR & issues templates should be managed globally for the organization. To do so, we must remove the templates for this repo.

Fixes #740

Type of change

Please delete options that are not relevant.

• Enhancement (non-breaking change which improves an existing functionality).

Is the solution different from the one proposed during the grooming?

No grooming for this task. The proposed solution in the original task has been followed.

Checklists

Generic development checklist

• [x] Any dependent changes have been merged and published in downstream modules.

Test summary

Not relevant