Eliminate an extra vector allocation for many attributes

[TimSylvester]

Eliminates a 1-element vector allocation on some attribute instances due to the default parameter value.

Remove the count parameter on static attribute declarations because they're always 1 and larger values aren't fully supported anyway.

[github-actions]

Bloaty Results 🐋

Compared to main

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  +0.0%    +720  -0.0%    -656    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results/pr-2049-compared-to-main.txt

Compared to d387090 (legacy)

    FILE SIZE        VM SIZE    
 --------------  -------------- 
   +19% +21.7Mi  +400% +23.9Mi    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results/pr-2049-compared-to-legacy.txt

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (ec9afb5) 85.70% compared to head (48d6cf5) 85.71%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2049      +/-   ##
==========================================
+ Coverage   85.70%   85.71%   +0.01%     
==========================================
  Files         569      569              
  Lines       28052    28052              
==========================================
+ Hits        24042    24045       +3     
+ Misses       4010     4007       -3     

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[github-actions]

Bloaty Results (iOS) 🐋

Compared to main

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  -0.0%     -16  [ = ]       0    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results-ios/pr-2049-compared-to-main.txt