fix: rever courier changes

[hperl]

These changes remove symbols currently needed on Ory Network.

Related issue(s)

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got the approval (please contact
  [email protected]) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

[codecov]

Codecov Report

Merging #3613 (9b5dfaa) into master (52639e6) will increase coverage by 0.12%.
Report is 1 commits behind head on master.
The diff coverage is 88.11%.

❗ Current head 9b5dfaa differs from pull request most recent head a47c528. Consider uploading reports for the commit a47c528 to get more accurate results

@@            Coverage Diff             @@
##           master    #3613      +/-   ##
==========================================
+ Coverage   78.15%   78.28%   +0.12%     
==========================================
  Files         342      342              
  Lines       23299    23378      +79     
==========================================
+ Hits        18210    18302      +92     
+ Misses       3711     3700      -11     
+ Partials     1378     1376       -2     

Files	Coverage Δ
courier/test/persistence.go	100.00% <100.00%> (ø)
selfservice/strategy/link/sender.go	71.17% <ø> (ø)
courier/courier_dispatcher.go	67.50% <68.75%> (+19.61%)	⬆️
courier/courier.go	72.22% <71.42%> (-6.57%)	⬇️
persistence/sql/persister_courier.go	86.50% <83.78%> (+1.40%)	⬆️

... and 2 files with indirect coverage changes