HDDS-15793. Bump ESLint to 9.39.4

[jshukla01]

Bump eslint version to v9.39.4.

Please describe your PR in detail:
Bumping the eslint version. From 9.0.0 onwards eslint expects flat config files hence added a new file and removed .eslintignore.

Tested it locally by running pnpm list on both v7 and v9 and the result were similar.

[spacemonkd]

Hi @jshukla01, thanks for this patch, it was long overdue.
have you tried running pnpm lint after this change?

[jshukla01]

Hi @jshukla01, thanks for this patch, it was long overdue. have you tried running pnpm lint after this change?

@spacemonkd Thanks for taking time for looking into it. Yes I did run pnpm lint after the changes and below is the comparison between v7 and v9.

grep "✖" /tmp/eslint7-baseline.log /tmp/eslint9-parity.log
/tmp/eslint7-baseline.log:✖ 2869 problems (104 errors, 2765 warnings)
/tmp/eslint9-parity.log:✖ 2842 problems (104 errors, 2738 warnings)

Attaching the full output of the run.
ESLint9.log

[spacemonkd]

Thanks @jshukla01 for the update.
This LGTM, +2.

Currently we do not have linter checks on JS, so we can handle these violations later on in a separate ticket. Would you like to raise an Apache JIRA and attach the error log, maybe you or someone from the community can pick it up later on.

[adoroszlai]

Thanks @jshukla01 for the patch. HDDS-15647 introduced conflicts, can you please resolve them?