Remove Google Tag Manager

[fiskus]

Previously, added in #3497

• Changelog entry (skip if change is not significant to end users, e.g. docs only)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 38.47%. Comparing base (4304d70) to head (e2377ab).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4039      +/-   ##
==========================================
+ Coverage   38.43%   38.47%   +0.03%     
==========================================
  Files         718      717       -1     
  Lines       33051    33023      -28     
  Branches     4670     4837     +167     
==========================================
  Hits        12704    12704              
+ Misses      19723    19695      -28     
  Partials      624      624              

Flag	Coverage Δ
api-python	90.75% <ø> (ø)
catalog	11.51% <ø> (+0.01%)	⬆️
lambda	87.96% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.