[Tests] avoid publishing "malformed package.json" test to avoid flawed security scanners

Fixes #319.
Fixes #318.
Fixes #317.
Fixes #314.
Closes #313.
Fixes #312.
Fixes #311.
Fixes #310.
Fixes #309.
Fixes #306.
Fixes #305.
Fixes #304.
Fixes #303.
Fixes #291.
Fixes #288.

Author: ljharb

package.json

@@ -65,7 +65,8 @@
 	"publishConfig": {
 		"ignore": [
 			".github/workflows",
-			"appveyor.yml"
+			"appveyor.yml",
+			"test/resolver/malformed_package_json"
 		]
 	}
 }

test/resolver.js

@@ -1,4 +1,5 @@
 var path = require('path');
+var fs = require('fs');
 var test = require('tape');
 var resolve = require('../');
 var async = require('../async');
@@ -539,14 +540,15 @@ test('absolute paths', function (t) {
     });
 });
 
-test('malformed package.json', function (t) {
+var malformedDir = path.join(__dirname, 'resolver/malformed_package_json');
+test('malformed package.json', { skip: !fs.existsSync(malformedDir) }, function (t) {
     /* eslint operator-linebreak: ["error", "before"], function-paren-newline: "off" */
     t.plan(
         (3 * 3) // 3 sets of 3 assertions in the final callback
         + 2 // 1 readPackage call with malformed package.json
     );
 
-    var basedir = path.join(__dirname, 'resolver/malformed_package_json');
+    var basedir = malformedDir;
     var expected = path.join(basedir, 'index.js');
 
     resolve('./index.js', { basedir: basedir }, function (err, res, pkg) {

test/resolver_sync.js

@@ -667,10 +667,11 @@ test('absolute paths', function (t) {
     t.end();
 });
 
-test('malformed package.json', function (t) {
+var malformedDir = path.join(__dirname, 'resolver/malformed_package_json');
+test('malformed package.json', { skip: !fs.existsSync(malformedDir) }, function (t) {
     t.plan(5 + (requireResolveSupportsPaths ? 1 : 0));
 
-    var basedir = path.join(__dirname, 'resolver/malformed_package_json');
+    var basedir = malformedDir;
     var expected = path.join(basedir, 'index.js');
 
     t.equal(