feat: add announceToTrainer in scheduler

[gaius-qi]

Description

• Add announceToTrainer in scheduler.

Related Issue

Motivation and Context

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #2371 (8ef19e6) into main (0cddb97) will decrease coverage by 0.22%.
The diff coverage is 7.43%.

@@            Coverage Diff             @@
##             main    #2371      +/-   ##
==========================================
- Coverage   49.71%   49.49%   -0.22%     
==========================================
  Files         148      148              
  Lines       19645    19754     +109     
==========================================
+ Hits         9766     9777      +11     
- Misses       9265     9365     +100     
+ Partials      614      612       -2     

Flag	Coverage Δ
Object-compatibility-e2etests	?
e2etests	?
unittests	49.49% <7.43%> (-0.22%)	⬇️

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

Impacted Files	Coverage Δ
scheduler/announcer/announcer.go	13.88% <1.75%> (-37.40%)	⬇️
scheduler/config/config.go	88.37% <100.00%> (+0.18%)	⬆️

... and 2 files with indirect coverage changes