chore: bump proxy-agent from 5.0.0 to 6.2.1 (#6247)

* chore: bump proxy-agent from 5.0.0 to 6.2.1

Bumps [proxy-agent](https://github.com/TooTallNate/proxy-agents/tree/HEAD/packages/proxy-agent) from 5.0.0 to 6.2.1.
- [Release notes](https://github.com/TooTallNate/proxy-agents/releases)
- [Changelog](https://github.com/TooTallNate/proxy-agents/blob/main/packages/proxy-agent/CHANGELOG.md)
- [Commits](https://github.com/TooTallNate/proxy-agents/commits/proxy-agent@6.2.1/packages/proxy-agent)

---
updated-dependencies:
- dependency-name: proxy-agent
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update proxy-agent usage

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Asher <ash@coder.com>

src/node/update.ts

@@ -1,7 +1,7 @@
 import { field, logger } from "@coder/logger"
 import * as http from "http"
 import * as https from "https"
-import ProxyAgent from "proxy-agent"
+import { ProxyAgent } from "proxy-agent"
 import * as semver from "semver"
 import * as url from "url"
 import { httpProxyUri, version } from "./constants"
@@ -104,7 +104,9 @@ export class UpdateProvider {
       const request = (uri: string): void => {
         logger.debug("Making request", field("uri", uri))
         const isHttps = uri.startsWith("https")
-        const agent = httpProxyUri ? new ProxyAgent(httpProxyUri) : undefined
+        const agent = new ProxyAgent({
+          getProxyForUrl: () => httpProxyUri || "",
+        })
         const httpx = isHttps ? https : http
         const client = httpx.get(uri, { headers: { "User-Agent": "code-server" }, agent }, (response) => {
           if (!response.statusCode || response.statusCode < 200 || response.statusCode >= 400) {