chore: eslint migration (#453)

## Description

```
> eslint src && prettier . --check


Oops! Something went wrong! :(

ESLint: [9](https://github.com/defenseunicorns/kubernetes-fluent-client/actions/runs/11673947912/job/32505660897?pr=399#step:5:10).14.0

ESLint couldn't find an eslint.config.(js|mjs|cjs) file.

From ESLint v9.0.0, the default configuration file is now eslint.config.js.
If you are using a .eslintrc.* file, please follow the migration guide
to update your configuration file to the new format:

https://eslint.org/docs/latest/use/configure/migration-guide

If you still have problems after following the migration guide, please stop by
https://eslint.org/chat/help to chat with the team.

npx @eslint/migrate-config .eslintrc.json

Migrating .eslintrc.json

Wrote new config to ./eslint.config.mjs

You will need to install the following packages to use the new config:
- globals
- @eslint/js
- @eslint/eslintrc

You can install them using the following command:

npm install globals @eslint/js @eslint/eslintrc -D
```

## Related Issue

Fixes #452 

<!-- or -->

Relates to #

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [x] Other (security config, docs update, etc)

## Checklist before merging

- [x] Test, docs, adr added or updated as needed
- [x] [Contributor Guide
Steps](https://docs.pepr.dev/main/contribute/#submitting-a-pull-request)
followed

---------

Signed-off-by: Case Wylie <[email protected]>

eslint.config.mjs

@@ -0,0 +1,66 @@
+import typescriptEslint from "@typescript-eslint/eslint-plugin";
+import globals from "globals";
+import tsParser from "@typescript-eslint/parser";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+});
+
+export default [
+  {
+    ignores: ["**/node_modules", "**/dist", "**/__mocks__", "e2e/crds", "e2e/crds"],
+  },
+  ...compat.extends(
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:jsdoc/recommended-typescript-error",
+  ),
+  {
+    plugins: {
+      "@typescript-eslint": typescriptEslint,
+    },
+
+    languageOptions: {
+      globals: {
+        ...Object.fromEntries(Object.entries(globals.browser).map(([key]) => [key, "off"])),
+      },
+
+      parser: tsParser,
+      ecmaVersion: 2022,
+      sourceType: "script",
+
+      parserOptions: {
+        project: ["tsconfig.json"],
+      },
+    },
+
+    rules: {
+      "class-methods-use-this": "warn",
+      "consistent-this": "warn",
+      "no-invalid-this": "warn",
+
+      "@typescript-eslint/no-floating-promises": [
+        "warn",
+        {
+          ignoreVoid: true,
+        },
+      ],
+
+      "jsdoc/tag-lines": [
+        "error",
+        "any",
+        {
+          startLines: 1,
+        },
+      ],
+    },
+  },
+];

package.json

@@ -49,6 +49,8 @@
   "devDependencies": {
     "@commitlint/cli": "19.5.0",
     "@commitlint/config-conventional": "19.5.0",
+    "@eslint/eslintrc": "^3.1.0",
+    "@eslint/js": "^9.14.0",
     "@jest/globals": "29.7.0",
     "@types/byline": "4.2.36",
     "@types/readable-stream": "4.0.18",
@@ -57,6 +59,7 @@
     "@typescript-eslint/eslint-plugin": "8.13.0",
     "@typescript-eslint/parser": "8.13.0",
     "eslint-plugin-jsdoc": "50.4.3",
+    "globals": "^15.12.0",
     "husky": "^9.1.6",
     "jest": "29.7.0",
     "lint-staged": "^15.2.10",