[Executor] Fix flex flow metrices

[lumoslnt]

Description

Currently, we always update metrices no matter whether the output of aggregation function is a dictionary or not, which is not reasonable. The expected output of aggregation function should be a dictionary, if not, we will skip metrices update and add a warning in logger.

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• CHANGELOG is updated for new features, bug fixes or other significant changes.
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Testing Guidelines

• Pull request includes test coverage for the included changes.

[github-actions]

promptflow SDK CLI Azure E2E Test Result dev/linatang/fix-flex-flow-aggregation-metrices

  4 files    4 suites   5m 2s ⏱️
238 tests 203 ✅  35 💤 0 ❌
952 runs  812 ✅ 140 💤 0 ❌

Results for commit acbb9bc.

♻️ This comment has been updated with latest results.

[github-actions]

SDK CLI Global Config Test Result dev/linatang/fix-flex-flow-aggregation-metrices

5 tests   5 ✅  1m 15s ⏱️
1 suites  0 💤
1 files    0 ❌

Results for commit acbb9bc.

♻️ This comment has been updated with latest results.

[github-actions]

Executor Unit Test Result dev/linatang/fix-flex-flow-aggregation-metrices

792 tests   792 ✅  3m 44s ⏱️
  1 suites    0 💤
  1 files      0 ❌

Results for commit acbb9bc.

♻️ This comment has been updated with latest results.

[github-actions]

Executor E2E Test Result dev/linatang/fix-flex-flow-aggregation-metrices

241 tests   236 ✅  5m 10s ⏱️
  1 suites    5 💤
  1 files      0 ❌

Results for commit acbb9bc.

♻️ This comment has been updated with latest results.

[github-actions]

promptflow-core test result

0 tests   0 ✅  0s ⏱️
0 suites  0 💤
0 files    0 ❌

Results for commit acbb9bc.

♻️ This comment has been updated with latest results.

[github-actions]

SDK CLI Test Result dev/linatang/fix-flex-flow-aggregation-metrices

    4 files      4 suites   58m 7s ⏱️
  663 tests   650 ✅ 13 💤 0 ❌
2 652 runs  2 600 ✅ 52 💤 0 ❌

Results for commit acbb9bc.

♻️ This comment has been updated with latest results.