Move reaper's skipSchemaMigration to ReaperTemplate

[a-mroz]

This way it should be available in both Reaper.spec and K8ssandraCluster.spec.reaper

What this PR does:

Which issue(s) this PR fixes:
Fixes #1667

Checklist

• Changes manually tested
• Automated Tests added/updated
• Documentation added/updated
• CHANGELOG.md updated (not required for documentation PRs)
• CLA Signed: DataStax CLA

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 59.12%. Comparing base (42de723) to head (8ac8b1c).
Report is 17 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1448      +/-   ##
==========================================
+ Coverage   59.02%   59.12%   +0.10%     
==========================================
  Files         125      125              
  Lines       12695    12708      +13     
==========================================
+ Hits         7493     7514      +21     
+ Misses       4524     4520       -4     
+ Partials      678      674       -4     

Files with missing lines	Coverage Δ
apis/reaper/v1alpha1/reaper_types.go	94.73% <ø> (ø)

... and 6 files with indirect coverage changes

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests

[adejanovski]

Looks good, and makes total sense to expose the field in the K8ssandraCluster spec.
Thanks for creating this PR!