tools: change editorconfig's 'ignore' to 'unset'

According to https://editorconfig.org/#supported-properties the
canonical way to disable a property is to set it to 'unset'. We did use
'ignore' and this generally works because tools ignore unknown values
but some of them like `eclint` are picky on it.

PR-URL: #28440
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

.editorconfig

@@ -16,11 +16,11 @@ indent_size = 8
 indent_style = tab
 
 [{deps}/**]
-charset = ignore
-end_of_line = ignore
-indent_size = ignore
-indent_style = ignore
-trim_trailing_whitespace = ignore
+charset = unset
+end_of_line = unset
+indent_size = unset
+indent_style = unset
+trim_trailing_whitespace = unset
 
 [{test/fixtures,deps,tools/node_modules,tools/gyp,tools/icu,tools/msvs}/**]
 insert_final_newline = false