docs: remove redundant statement about files attribute (#6557)

Remove redundant and inaccurate statement about the "package.json#files" field

The statement:

'Files included with the "package.json#files" field cannot be excluded through `.npmignore` or `.gitignore`'.

Is inaccurate and redundant as the concept is already being explained right above:

'You can also provide a `.npmignore` file in the root of your package or in subdirectories, which will keep files from being included. At the root of your package it will not override the "files" field, but in subdirectories it will. The `.npmignore` file works just like a `.gitignore.` If there is a `.gitignore` file, and `.npmignore` is missing, `.gitignore`'s contents will be used instead'.

docs/lib/content/configuring-npm/package-json.md

@@ -279,9 +279,6 @@ it will. The `.npmignore` file works just like a `.gitignore`. If there is
 a `.gitignore` file, and `.npmignore` is missing, `.gitignore`'s contents
 will be used instead.
 
-Files included with the "package.json#files" field _cannot_ be excluded
-through `.npmignore` or `.gitignore`.
-
 Certain files are always included, regardless of settings:
 
 * `package.json`