Bug 36400: (follow-up) remove option editorconfig from .prettierrc.js

- The option doesn't seem do what it's intended for:
	- The debug logs still show options from the .editorconfig (which is actually what we want in this case).
- The option causes unwanted warnings when using the cli.
- In summary: we have to keep in mind that the rules are now hierarchical:
	1. .editorconfig
	2. .prettierrc.js

Signed-off-by: Brendan Lawlor <blawlor@clamsnet.org>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>

.prettierrc.js

@@ -1,6 +1,5 @@
 module.exports = {
     arrowParens: "avoid",
-    editorconfig: "false",
     trailingComma: "es5",
     overrides: [
         {