chore: implement Delete config policies API handlers

[amandavialva01]

Ticket

CM-488

Description

Implement API handlers for Delete config policies for workspace-level and global scopes.

Test Plan

CI passes (automated testing).

Checklist

• Changes have been manually QA'd
• New features have been approved by the corresponding PM
• User-facing API changes have the "User-facing API Change" label
• Release notes have been added as a separate file under docs/release-notes/
  See Release Note for details.
• Licenses have been included for new code which was copied and/or modified from any external code

[netlify]

✅ Deploy Preview for determined-ui canceled.

Name	Link
🔨 Latest commit	3a40afa
🔍 Latest deploy log	https://app.netlify.com/sites/determined-ui/deploys/66e8b91ba9cc86000830f4ec

[codecov]

Codecov Report

Attention: Patch coverage is 85.36585% with 6 lines in your changes missing coverage. Please review.

Project coverage is 54.51%. Comparing base (062cb52) to head (3a40afa).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
master/internal/api_config_policies.go	85.29%	5 Missing ⚠️
...ternal/configpolicy/postgres_task_config_policy.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #9927   +/-   ##
=======================================
  Coverage   54.50%   54.51%           
=======================================
  Files        1253     1252    -1     
  Lines      156630   156654   +24     
  Branches     3599     3600    +1     
=======================================
+ Hits        85368    85396   +28     
+ Misses      71129    71125    -4     
  Partials      133      133           

Flag	Coverage Δ
backend	45.17% <85.36%> (+0.03%)	⬆️
harness	72.75% <ø> (ø)
web	54.28% <ø> (ø)

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

Files with missing lines	Coverage Δ
master/internal/configpolicy/utils.go	95.83% <100.00%> (ø)
...ternal/configpolicy/postgres_task_config_policy.go	93.44% <83.33%> (+4.38%)	⬆️
master/internal/api_config_policies.go	48.61% <85.29%> (+48.61%)	⬆️

... and 4 files with indirect coverage changes

[kkunapuli]

Nice work! Left some comments.

[kkunapuli]

LGTM - great work!

[kkunapuli]

Nice callout / reminder.

[kkunapuli]

This was a great idea. Just a little ahead of its time, perhaps. Thanks for keeping the codebase clean!