Tooling: Remove some redundant max-len patterns

- `///` is not used in any linted files.
  It is/was used in webpack dist, but those are not and should not
  be passed through ESLint.
- `QUnit` was presumably added prematurely on the assumption
  that overly long test names should not be broken over multiple
  lines. However, being strings, they are already ignored.
- `// (?!eslint..)` was redundant. Ignoring warnings from max-len
  about an eslint-disable line has no influence on the actual
  parsing of those lines by ESLint.

Follows-up 807100b.

Bug: T185295
Change-Id: I2be2492848190b53d45240b38a08784b4a370819

.eslintrc.json

@@ -24,12 +24,10 @@
 				"warn",
 				{
 					"tabWidth": 2,
-					// Note: exclude all eslint- directives except for max-len itself
-					// since `// eslint-disable-line max-len` would cause this line to be
-					// ignored AND this rule to be disabled which would trigger
-					// --report-unused-disable-directives. By excluding max-len, the effect
-					// is to consider the line but disable this rule.
-					"ignorePattern": "^/// .+|// (?!eslint-.+max-len)eslint-.+|QUnit.",
+					// Exclude by default:
+					// - `eslint-` directives. To avoid having to disable
+					//   eslint for a long eslint-disable line.
+					"ignorePattern": "^// eslint-.+",
 					"ignoreUrls": true,
 					"ignoreComments": false,
 					"ignoreRegExpLiterals": true,