fix: Replace deprecated APIs

[coliff]

Summary of Code Changes

1. Removed Deprecated ProposedFeatures.all

Before:

let connection: Connection = createConnection(ProposedFeatures.all);

After:

let connection: Connection = createConnection();

---

2. Removed Deprecated ErrorMessageTracker

Before:

import { ErrorMessageTracker } from "vscode-languageserver/node";
// ...
let tracker = new ErrorMessageTracker();
documents.forEach((document) => {
  try {
    validateTextDocument(connection, document);
  } catch (err) {
    tracker.add(getErrorMessage(err, document));
  }
});
tracker.sendErrors(connection);

After:

const errors: string[] = [];
documents.forEach((document) => {
  try {
    validateTextDocument(connection, document);
  } catch (err) {
    errors.push(getErrorMessage(err, document));
  }
});
if (errors.length > 0) {
  connection.window.showErrorMessage(errors.join('\n'));
}

---

3. Converted CommonJS require() to ES6 Imports

Before:

import fs = require("fs");
let stripJsonComments: any = require("strip-json-comments");

After:

import * as fs from "fs";
import stripJsonComments from "strip-json-comments";

---

4. Improved Typing for linter and Configs

Before:

let linter: any = null;
let htmlhintrcOptions: any = {};
function getConfiguration(filePath: string): any { ... }
function findConfigForHtmlFile(base: string) { ... }
function loadConfigurationFile(configFile: string): any { ... }

After:

let linter: { verify: (text: string, config?: HtmlHintConfig) => htmlhint.Error[] } | null = null;
let htmlhintrcOptions: Record<string, HtmlHintConfig | null | undefined> = {};
function getConfiguration(filePath: string): HtmlHintConfig { ... }
function findConfigForHtmlFile(base: string): HtmlHintConfig | undefined { ... }
function loadConfigurationFile(configFile: string): HtmlHintConfig | null { ... }

---

5. Safer Assignment for linter

Before:

linter = htmlhint.default || htmlhint.HTMLHint || htmlhint;

After:

linter = (htmlhint.default || htmlhint.HTMLHint || htmlhint) as typeof linter;

---

6. Other Minor Type Improvements

• Used more specific types for settings and configuration objects.
• Updated function signatures to reflect improved types.

---

These changes modernize the code, remove deprecated APIs, and improve type safety.

[gemini-code-assist]

Code Review

The pull request focuses on modernizing the codebase by removing deprecated APIs, improving type safety, and enhancing error handling. The changes are well-structured and contribute to the overall maintainability and reliability of the HTMLHint server.