Remove old, unused .wasm files from @php-wasm/web (#2847)

## Motivation for the change, related issues

We cleaned up old PHP versions for @php-wasm/node but forgot to cleanup
those for @php-wasm/web. This PR fixes that.

## Implementation details

Deletes two unused PHP 8.3 builds and two unused PHP 8.4 builds from
@php-wasm/web.

## Testing Instructions (or ideally a Blueprint)

- CI

Author: brandonpayton