Remove sysimg creation workaround.

[maleadt]

https://github.com/JuliaLang/julia/pull/37530 is part of 1.8+, and PackageCompiler.jl requires Julia 1.10.

Closes https://github.com/JuliaLang/PackageCompiler.jl/issues/839.

[codecov[bot]]

Codecov Report

:x: Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review. :white_check_mark: Project coverage is 86.02%. Comparing base (2d2e8b3) to head (97a46fc).

Files with missing lines	Patch %	Lines
src/PackageCompiler.jl	75.00%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1054      +/-   ##
==========================================
- Coverage   86.16%   86.02%   -0.15%     
==========================================
  Files           3        3              
  Lines         795      787       -8     
==========================================
- Hits          685      677       -8     
  Misses        110      110              

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[KristofferC]

👍 CI failure is probably unrelated.

[KristofferC]

Actually CI on https://github.com/JuliaLang/PackageCompiler.jl/pull/1057 looks better than here. I'll try rebase this.