deps: Update JS/JL revisions and adapt to JuliaLang/julia#62862

[aviatesk]

Update the JuliaSyntax/JuliaLowering pins from 2fefd0127e to 537a4c16f1. The JuliaLowering bugfix batch JuliaLang/julia#62862 included in this range changes two behaviors JETLS relied on, so this commit also adapts the affected code paths:

• Old-style macro invocation failures are now rethrown wrapped as LoadError(file, line, MacroExpansionError(...)) instead of a bare MacroExpansionError, so the err isa JL.MacroExpansionError check in per_stmt_diagnostics! no longer matched and macro expansion error diagnostics silently disappeared. The catch handler now unwraps the LoadError before dispatching on the error type.

• expand_struct_def/expand_typegroup_def now emit an explicit global declaration for the type name ahead of the lowered definition. That node resolves to a :global binding distinct from the internal one the type-alias normalization in compute_binding_occurrences re-keys onto, so the struct name gained a duplicate :decl occurrence. Such same-(mod, name) global entries are now folded into the alias target, skipping occurrences already covered at the same byte range.

Both regressions were caught by the existing test suite (test_lowering_diagnostic.jl and test_occurrence_analysis.jl); the full suite passes with this commit.

[codecov]

Codecov Report

❌ Patch coverage is 94.44444% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 79.90%. Comparing base (6cdac63) to head (ed07e64).
⚠️ Report is 7 commits behind head on master.

Files with missing lines	Patch %	Lines
src/analysis/occurrence-analysis.jl	93.75%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #883      +/-   ##
==========================================
+ Coverage   79.89%   79.90%   +0.01%     
==========================================
  Files          63       63              
  Lines       14103    14121      +18     
==========================================
+ Hits        11267    11284      +17     
- Misses       2836     2837       +1     

Flag	Coverage Δ
JETLS.jl	79.90% <94.44%> (+0.01%)	⬆️

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