chore(remix): replace yargs with native util.parseArgs

[roli-lpci]

Replaces the yargs dependency in @sentry/remix with Node's built-in util.parseArgs for CLI argument parsing in the sentry-upload-sourcemaps script.

• If you've added code that should be tested, please add tests.
• Ensure your code lints and the test suite passes (yarn lint) & (yarn test).
• Link an issue if there is one related to your pull request.

Ref #19447

What this does

Replaces yargs with util.parseArgs (built-in since Node 18.3) for parsing CLI flags in the source map upload script. Adds --keepAfterUpload flag as a cross-version alternative to yargs' --no-deleteAfterUpload boolean negation.

Removes yargs and ~10 transitive dependencies (cliui, escalade, string-width, y18n, yargs-parser, wrap-ansi, etc.).

Behavioral changes from yargs

• Unknown flags now throw an error (yargs silently ignored them). This catches typos like --relase early.
• Kebab-case aliases (--url-prefix) no longer work. Use the documented camelCase names (--urlPrefix).
• Boolean flags no longer accept =true/=false syntax. Use the bare flag (--disableDebugIds) to enable, or --keepAfterUpload to prevent source map deletion.

Why --keepAfterUpload?

util.parseArgs does not support boolean negation (--no-deleteAfterUpload) on Node < 20.16. Since @sentry/remix supports Node >= 18, --keepAfterUpload provides a cross-version way to prevent source map deletion after upload.

[sentry]

Bug: The script uses util.parseArgs, which will crash on Node.js versions 18.0.0-18.2.x, despite the package.json allowing these versions.
_{Severity: MEDIUM}

Suggested Fix

Update the package.json engines field to require "node": ">=18.3.0". Alternatively, add a runtime check for util.parseArgs and provide a helpful error message or a fallback implementation for older Node.js versions.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: packages/remix/scripts/sentry-upload-sourcemaps.js#L2

Potential issue: The `sentry-upload-sourcemaps.js` script utilizes the `util.parseArgs`
function, which is only available in Node.js versions 18.3.0 and later. The project's
`package.json` declares support for Node.js version 18.0.0 and above (`"node": ">=18"`).
Consequently, users running the script on Node.js versions between 18.0.0 and 18.2.x
will encounter a runtime crash because the `util.parseArgs` function does not exist in
their environment. The current CI setup does not test against these specific older patch
versions of Node 18, so this issue would not be caught automatically.

_{Did we get this right? 👍 / 👎 to inform future reviews.}