ci: only run lint on latest node.js + unix

Problem:

     neovim@5.4.1-dev.0 lint
    > prettier --check . && eslint --format=unix --ignore-pattern 'packages/example*/**' --ignore-pattern 'packages/neovim/lib/**/*.js' .
    ESLint: 9.34.0
    TypeError: object.split(...).toReversed is not a function
        at createTraceMap (file:///D:/a/node-client/node-client/node_modules/eslint-plugin-unicorn/rules/utils/global-reference-tracker.js:6:33)
        at new GlobalReferenceTracker (file:///D:/a/node-client/node-client/node_modules/eslint-plugin-unicorn/rules/utils/global-reference-tracker.js:27:34)
        at file:///D:/a/node-client/node-client/node_modules/eslint-plugin-unicorn/rules/no-document-cookie.js:8:17
        at ModuleJob.run (node:internal/modules/esm/module_job:195:25)

Solution:
Only run lint task on latest nodejs

Author: justinmk

.github/workflows/ci.yml

@@ -80,8 +80,8 @@ jobs:
         run: npm run build
 
       - name: lint
-        # Skip on old Node.js, devDependencies use newish JS features.
-        if: matrix.node != '14'
+        # Only run lint on latest Node.js, because devDependencies use new JS features.
+        if: matrix.node == '20' && runner.os != 'Windows'
         run: npm run lint
 
       - name: test