DMCA does not include fair use as an allowable reason to circumvent DRM. That is one of the reasons why DRM sometimes shows up in weird places because it effectively limits fair use rights (see also all the right to repair stuff that people have been talking sbout lately)
>DMCA does not include fair use as an allowable reason to circumvent DRM. //
Could you cite the law you're referring to here please?
The UK CDPA as amended to follow the EU's Marrakech directive seems to say anything that prevents you from exercising your Fair Dealing rights to make content accessible for disabled people is void if it contradicts these rights. This seems necessarily to allow for circumvention of DRM (for people with disabilities and specific registered companies) but that also appears to mean production of circumvention means needs to be legal otherwise such accessibility will be impossible.
DMCA is the Digital Millennium Copyright Act, the latest amendment to USA copyright law. Text of the law is here: https://www.copyright.gov/legislation/dmca.pdf . GitHub is a division of a US company, Microsoft, so it is bound by US law.
IANAL