Remove support for Python 3.8

[luigiw]

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.
• I confirm that all new dependencies are compatible with the MIT license.
• 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]

promptflow SDK CLI Azure E2E Test Result deprecate-py38

  3 files    3 suites   3m 16s ⏱️
244 tests 204 ✅  40 💤 0 ❌
732 runs  612 ✅ 120 💤 0 ❌

Results for commit f8dd7c2.

[github-actions]

promptflow-core test result

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

Results for commit f8dd7c2. ± Comparison against base commit e8641e6.

[github-actions]

SDK CLI Global Config Test Result deprecate-py38

6 tests   6 ✅  1m 20s ⏱️
1 suites  0 💤
1 files    0 ❌

Results for commit f8dd7c2.

[github-actions]

Executor Unit Test Result deprecate-py38

798 tests   797 ✅  3m 43s ⏱️
  1 suites    0 💤
  1 files      1 ❌

For more details on these failures, see this check.

Results for commit f8dd7c2.

[github-actions]

promptflow-tracing test result

  9 files   -   3    9 suites   - 3   13s ⏱️ -4s
 62 tests ±  0   62 ✅ ±  0  0 💤 ±0  0 ❌ ±0 
558 runs   - 186  558 ✅  - 186  0 💤 ±0  0 ❌ ±0 

Results for commit f8dd7c2. ± Comparison against base commit e8641e6.

[github-actions]

promptflow-evals test result

  9 files   -   3    9 suites   - 3   1h 21m 16s ⏱️ + 1h 3m 48s
 64 tests  -  61   61 ✅  -  64   3 💤 + 3  0 ❌ ±0 
576 runs   - 924  549 ✅  - 951  27 💤 +27  0 ❌ ±0 

Results for commit f8dd7c2. ± Comparison against base commit e8641e6.

This pull request removes 125 and adds 64 tests. Note that renamed tests count towards both.

tests.evals.unittests.test_batch_run_context.TestBatchRunContext ‑ test_batch_timeout_custom
tests.evals.unittests.test_batch_run_context.TestBatchRunContext ‑ test_batch_timeout_default
tests.evals.unittests.test_batch_run_context.TestBatchRunContext ‑ test_with_codeclient
tests.evals.unittests.test_batch_run_context.TestBatchRunContext ‑ test_with_pfclient
tests.evals.unittests.test_built_in_evaluator.TestBuiltInEvaluators ‑ test_fluency_evaluator
tests.evals.unittests.test_built_in_evaluator.TestBuiltInEvaluators ‑ test_fluency_evaluator_empty_string
tests.evals.unittests.test_built_in_evaluator.TestBuiltInEvaluators ‑ test_fluency_evaluator_non_string_inputs
tests.evals.unittests.test_chat_evaluator.TestChatEvaluator ‑ test_conversation_validation_invalid_citations
tests.evals.unittests.test_chat_evaluator.TestChatEvaluator ‑ test_conversation_validation_missing_role
tests.evals.unittests.test_chat_evaluator.TestChatEvaluator ‑ test_conversation_validation_normal
…

tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_chat[False-True]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_chat[True-True]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_content_safety
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_content_safety_chat[False-False]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_content_safety_chat[True-False]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_qa[False]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_qa[True]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_qa_for_nans
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_qa_with_openai_config[False]
tests.evals.e2etests.test_builtin_evaluators.TestBuiltInEvaluators ‑ test_composite_evaluator_qa_with_openai_config[True]
…

♻️ This comment has been updated with latest results.

[github-actions]

Executor E2E Test Result deprecate-py38

245 tests   239 ✅  5m 10s ⏱️
  1 suites    6 💤
  1 files      0 ❌

Results for commit f8dd7c2.

[github-actions]

SDK CLI Test Result deprecate-py38

    3 files      3 suites   49m 30s ⏱️
  790 tests   730 ✅ 23 💤  37 ❌
2 370 runs  2 190 ✅ 69 💤 111 ❌

For more details on these failures, see this check.

Results for commit f8dd7c2.