Makes linkcheck not build the examples

[eddiebergman]

Linkcheck was causing the examples to be built again but that is already done in the doc.yaml workflow with make html.

• Makes the linkcheck not run the examples when done locally
• Should half the time for docs to build in the workflow.

[codecov]

Codecov Report

Merging #1231 (c307394) into development (4597152) will decrease coverage by 0.03%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           development    #1231      +/-   ##
===============================================
- Coverage        88.17%   88.13%   -0.04%     
===============================================
  Files              138      138              
  Lines            10866    10866              
===============================================
- Hits              9581     9577       -4     
- Misses            1285     1289       +4     

Impacted Files	Coverage Δ
...ine/components/feature_preprocessing/kernel_pca.py	94.73% <0.00%> (-1.76%)	⬇️
...learn/pipeline/components/regression/libsvm_svr.py	90.24% <0.00%> (-1.22%)	⬇️
...ine/components/classification/gradient_boosting.py	93.04% <0.00%> (-0.87%)	⬇️
autosklearn/evaluation/abstract_evaluator.py	92.12% <0.00%> (-0.79%)	⬇️
...ature_preprocessing/select_rates_classification.py	87.32% <0.00%> (+1.40%)	⬆️

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[mfeurer]

I doubt that this halves the runtime as examples aren't re-run in case they weren't changed. But I don't mind merging this.

[eddiebergman]

Ahh good point, I was thinking from the local perspective more where normally it's a fresh build or I run make clean in between. Either way, it makes it faster to run for contributors or ourselves