Update ESLint and related packages

Major update breaking changes:
- ESLint 7.0.0 (https://eslint.org/docs/user-guide/migrating-to-7.0.0) now includes
.eslint.rc.js in its list, which is fine for us. Other changes are not applicable
for us.
- eslint-plugin-mocha (https://github.com/lo1tuma/eslint-plugin-mocha/blob/master/CHANGELOG.md#700-may-13-2020)
drops support for ESLint <7, but this CL updates to 7+. Other changes are
not applicable for us.

DISABLE_THIRD_PARTY_CHECK=Updating ESLint
R=petermarshall@chromium.org

Change-Id: I7760e084ef87f73a92f9ea4e075fb4c065047f5a
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2534873
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
diff --git a/node_modules/shebang-regex/index.js b/node_modules/shebang-regex/index.js
index d052d2e..63fc4a0 100644
--- a/node_modules/shebang-regex/index.js
+++ b/node_modules/shebang-regex/index.js
@@ -1,2 +1,2 @@
 'use strict';
-module.exports = /^#!.*/;
+module.exports = /^#!(.*)/;