docs: adapt KeptnTask example to changes in API

[bacherfl]

Closes #2120

[netlify]

✅ Deploy Preview for keptn-lifecycle-toolkit ready!

Name	Link
🔨 Latest commit	858c5b6
🔍 Latest deploy log	https://app.netlify.com/sites/keptn-lifecycle-toolkit/deploys/65083314afe91a0008599e68
😎 Deploy Preview	https://deploy-preview-2124--keptn-lifecycle-toolkit.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[agardnerIT]

LGTM

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[codecov]

Codecov Report

Merging #2124 (1ab3599) into main (d08df40) will increase coverage by 26.15%.
Report is 4 commits behind head on main.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2124       +/-   ##
===========================================
+ Coverage   58.26%   84.41%   +26.15%     
===========================================
  Files          35      151      +116     
  Lines        2389     9601     +7212     
===========================================
+ Hits         1392     8105     +6713     
- Misses        859     1213      +354     
- Partials      138      283      +145     

see 130 files with indirect coverage changes

Flag	Coverage Δ
certificate-operator	68.55% <ø> (ø)
component-tests	59.37% <ø> (+1.51%)	⬆️
lifecycle-operator	84.94% <ø> (?)
metrics-operator	86.56% <ø> (?)
scheduler	32.12% <ø> (ø)

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