Update to Clang.jl 0.19

[benegee]

When instantiating the dev project with julia 1.12.6 I get

ERROR: Unsatisfiable requirements detected for package libLLVM_jll [8f36deef]:
 libLLVM_jll [8f36deef] log:
 ├─possible versions are: 18.1.7 or uninstalled
 └─found to have no compatible versions left with Clang_jll [0ee61d77]
   └─Clang_jll [0ee61d77] log:
     ├─possible versions are: 9.0.1 - 21.1.8 or uninstalled
     ├─restricted by julia compatibility requirements to versions: 9.0.1 - 20.1.8 or uninstalled
     └─restricted by compatibility requirements with Clang [40e3b903] to versions: 12.0.0 - 16.0.6
       └─Clang [40e3b903] log:
         ├─possible versions are: 0.7.0 - 0.19.3 or uninstalled
         └─restricted to versions 0.18 by project [7c77d20e], leaving only versions: 0.18.0 - 0.18.3
           └─project [7c77d20e] log:
             ├─possible versions are: 0.0.0 or uninstalled
             └─project [7c77d20e] is fixed to version 0.0.0