fix: use the correct redirect_uri for linkedin social login

[kmherrmann]

LinkedIn Social Login shows the oryapis.com URL as the redirect target in the UI to the user, even when a custom domain is configured.
This works correctly on other social login providers. This PR points the flow to the right domain.

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
  security@ory.sh) 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

Reported in Community Slack

[codecov]

Codecov Report

Merging #3269 (27a654c) into master (2f844ec) will increase coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head 27a654c differs from pull request most recent head ac7fb04. Consider uploading reports for the commit ac7fb04 to get more accurate results

@@           Coverage Diff           @@
##           master    #3269   +/-   ##
=======================================
  Coverage   78.14%   78.15%           
=======================================
  Files         324      324           
  Lines       20763    20762    -1     
=======================================
+ Hits        16226    16227    +1     
+ Misses       3331     3330    -1     
+ Partials     1206     1205    -1     

Impacted Files	Coverage Δ
selfservice/strategy/oidc/provider_linkedin.go	64.47% <100.00%> (ø)

... and 2 files with indirect coverage changes

[Benehiko]

LGTM