Exclude parsing of `public` statements in Julia v1.10 CI

[gdalle]

See also

Is Compat.jl worth it for the `public` keyword?

With the introduction of public by @Lilith, many packages will want to mark their unexported public symbols that way. Since public is only available in Julia 1.11, the current recommended way to do this in 1.10 is with the Compat.jl package. Before we add it everywhere, I’m wondering if there are any negative side effects to it? @stevengj seems to think it’s fine but I’d love to get other opinions. In particular, it depends on 4 stdlibs: Dates, LinearAlgebra, TOML and UUIDs.