Recommend pip instead of conda for installation

[joamatab]

• Recommend pip instead of conda for installation
• deprecate plot_kweb and plot_matplotlib
• move most dependencies from pip install gdsfactory[cad] into pip install gdsfactory

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (de8ca20) 72.64% compared to head (0565916) 72.64%.

Files	Patch %	Lines
gdsfactory/component.py	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2433      +/-   ##
==========================================
- Coverage   72.64%   72.64%   -0.01%     
==========================================
  Files         366      366              
  Lines       23260    23261       +1     
  Branches     3787     3787              
==========================================
  Hits        16897    16897              
- Misses       5235     5236       +1     
  Partials     1128     1128              

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