fix: replace fs.R_OK with fs.constants.R_OK

[alikehel]

Pull Request check-list

• Does npm run test pass with this change (including linting)?
• Does the description below contain a link to an existing issue (Closes #[issue]) or a description of the issue you are solving?
• Have you added new tests to prevent regressions?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?

Description of change

• Replace fs.R_OK with fs.constants.R_OK since it got deprecated in node 24

References

• https://nodejs.org/en/blog/release/v24.0.0
  • b02cd411c2 - (SEMVER-MAJOR) fs: runtime deprecate fs.F_OK, fs.R_OK, fs.W_OK, fs.X_OK (Livia Medeiros) #49686
• doc: deprecate fs.F_OK, fs.R_OK, fs.W_OK, fs.X_OK nodejs/node#49683

[WikiRik]

Thanks!