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
JuliaLang/JuliaSyntax.jl#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
JuliaLang/JuliaSyntax.jl#377. Thus some
careful management of the JuliaSyntax-0.4.x branch for now.

(cherry picked from commit 85d7cca)

deps/JuliaSyntax.version

@@ -1,4 +1,4 @@
 JULIASYNTAX_BRANCH = main
-JULIASYNTAX_SHA1 = 045d156c44dbb87769c7416d049a7c08908539d4
+JULIASYNTAX_SHA1 = 4f1731d6ce7c2465fc21ea245110b7a39f34658a
 JULIASYNTAX_GIT_URL := https://github.com/JuliaLang/JuliaSyntax.jl.git
 JULIASYNTAX_TAR_URL = https://api.github.com/repos/JuliaLang/JuliaSyntax.jl/tarball/$1

deps/checksums/JuliaSyntax-4f1731d6ce7c2465fc21ea245110b7a39f34658a.tar.gz/md5

@@ -0,0 +1 @@
+8c9d9579eeab1ba40f978a32c9db9900

deps/checksums/JuliaSyntax-4f1731d6ce7c2465fc21ea245110b7a39f34658a.tar.gz/sha512

@@ -0,0 +1 @@
+1bdad624f61482b55deba8727fea1c087bfaea9e1f8afa3b44b984441fb7e663dac067baa4a96ae2d4cbd4a46ae8c87e9d20d2dfcd17046ad194711304184e57