update sinatra to latest version

[alexskr]

ontologies_api has a number of potential security vulnerabilities related to an outdated version of sinatra (and rack v4) so it should be updated to newer version, 2+

[alexskr]

Sinatra v1 has compatibility issues with with ruby v3.1+

[syphax-bouazzouni]

Done in AgroPortal, you can see this PR ontoportal-lirmm#121. if you want to see the changes,