Bump JuliaSyntax to 0.4.7 (#52136)
This fixes a whole bunch of small but annoying bugs, as described in the
JuliaSyntax-0.4.7 release notes
https://github.com/JuliaLang/JuliaSyntax.jl/releases/tag/v0.4.7
I've been careful about cutting the JuliaSyntax-0.4.7 release from
nonbreaking changes, so we should be able to backport this to 1.10.
---
Extended notes about compatibility
* The public keyword in
https://github.com/JuliaLang/JuliaSyntax.jl/pull/320 is released in
JuliaSyntax-0.4.7 but JuliaSyntax is multi-version aware so this is
disabled when used as the default parser in Julia 1.10, but is enabled
in 1.11-DEV. So should be backportable.
* We aim for parsing to `Expr` to always be stable in JuliaSyntax and
independent of the host Julia `VERSION`, but we're not fully there yet
for 1.11 / 1.10 due to
https://github.com/JuliaLang/JuliaSyntax.jl/issues/377. Thus some
careful management of the JuliaSyntax-0.4.x branch for now.
