[prompty] load_flow(source=path/to/prompty) is callable

[lalala123123]

Description

Please add an informative description that covers that changes made by the pull request and link all relevant issues.

All Promptflow Contribution checklist:

• The pull request does not introduce [breaking changes].
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.
• Create an issue and link to the pull request to get dedicated review from promptflow team. Learn more: suggested workflow.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[github-actions]

SDK CLI Global Config Test Result zhrua/load_prompty

5 tests   5 ✅  1m 24s ⏱️
1 suites  0 💤
1 files    0 ❌

Results for commit 0fb07dd.

♻️ This comment has been updated with latest results.

[github-actions]

promptflow SDK CLI Azure E2E Test Result zhrua/load_prompty

  4 files    4 suites   4m 58s ⏱️
238 tests 203 ✅  35 💤 0 ❌
952 runs  812 ✅ 140 💤 0 ❌

Results for commit 0fb07dd.

[github-actions]

Executor Unit Test Result zhrua/load_prompty

792 tests   792 ✅  3m 43s ⏱️
  1 suites    0 💤
  1 files      0 ❌

Results for commit 0fb07dd.

[github-actions]

Executor E2E Test Result zhrua/load_prompty

241 tests   235 ✅  5m 11s ⏱️
  1 suites    5 💤
  1 files      1 ❌

For more details on these failures, see this check.

Results for commit 0fb07dd.

♻️ This comment has been updated with latest results.

[github-actions]

SDK CLI Test Result zhrua/load_prompty

    4 files      4 suites   57m 32s ⏱️
  663 tests   650 ✅ 13 💤 0 ❌
2 652 runs  2 600 ✅ 52 💤 0 ❌

Results for commit 0fb07dd.