Update .readthedocs.yml (#628) #1160
linux.yml
on: push
GNU GCC 9
11m 36s
GNU GCC 10
12m 36s
GNU GCC 10 (c++20)
13m 40s
GNU GCC 12
14m 5s
Clang 11
9m 9s
Clang 13
9m 41s
Compile everything (GCC 9)
15m 27s