- symfony/polyfill-php80 installed to introduce the polyfill and support php7.3 using php8 functions
- symfony/polyfill-ctype installed to introduce ctype functions in case somebody doesn't have the ctype extension installed
- @version in file header level isn't used on code docs, it is intended
for API versions at class or method level
- avoids needing to update all these files on version increment
- avoids needing to regenerate SRI hashes for privatebin.js through
extra phpunit run
- simplifies VERSION_FILES list
- avoids having to filter above list during loop
- adds a few missing doc bloc headers