%let thisMacro=listrepofiles;
filename mcode temp;
proc http url="https://raw.githubusercontent.com/SASJedi/sas-macros/master/%qlowcase(&thisMacro).sas"
out=mcode;
run;
%include mcode /source2;
filename mcode;
%&thismacro(?)

This part of your code works for me if I modify the PROC HTTP statement to have the PROXYHOST= and PROXYPORT= and PROXYUSERNAME= and PROXYPASSWORD= options. Great.

The next part