* Update tests for Latexify 0.16.5

Behaviour was changed such that ã becomes \tilde{a}, instead of
\textnormal{\~{a}}.

* Test Julia 1.6 on x86 macOS instead of ARM

See: https://discourse.julialang.org/t/how-to-fix-github-actions-ci-failures-with-julia-1-6-or-1-7-on-macos-latest-and-macos-14/117019

* Bump GR compat and Plots version number

* update plotly show methods for PlotlyKaleido v2

* remove Pkg

* add it back

---------

Co-authored-by: Simon Christ <christ@cell.uni-hannover.de>

 - Disabled reference tests 25 and 30, which require StatsPlots support,
   for all backends (in PlotsBase/src/examples.jl)
 - Separate tests that are skipped and tests that are known to be broken
   due to upstream issues
 - Re-enable reference test 41 as upstream issue has been fixed
   (JuliaLang/julia#47261)
 - Disable reference test 50 because of upstream issue
   (jheinen/GR.jl#550)