Update icon after 20 years

I have worked on updating the icon of PHP on Windows, so I need some feedback regarding the change and the overall look. Main reason for this change is to make the icon more legible by means of changing the contrast and the outline around the 'php' text, as well as having the icon downsampled from a bigger base image which results in anti-aliased edges, thus making this icon adhere to modern design standards. This change also affects how Windows platforms display the icon in File Explorer, where previously the icon has always defaulted to 16x16 now it can display up to 256x256. Such change is also reflected on file assocations that point to 'php.exe', therefore the icon for those assocations match their "Default app". More information on this pr: https://github.com/php/php-src/pull/12016 Thanks.