By default, evaluation of code blocks is disabled (org-confirm-babel-evaluate is t by default in async Emacs process). If the org file contains section like this :

#+NAME: lsp-dir
#+begin_src emacs-lisp :tangle no
(expand-file-name "var/lsp/server" user-emacs-directory)
#+end_src

The auto-tangle process does not work :

• with Emacs 27, the async process does not end (like issue Tangling of file get indefinitely stopped by source block evaluation waiting for result #11)
• with Emacs 28, lsp-dir is set to nil and so is unusable

As code block evaluation can lead to code execution form untrusted org-file, it's dangerous to enabled it globally. This PR define a safelist variable in order to enable code block evaluation only for an explicit list of files.