[Internal] Test that Jobs API endpoints are pinned to 2.1 (#714)

## Changes
<!-- Summary of your changes that are easy to understand -->
Added tests to make sure regeneration is not going to break API version
pinning: databricks/databricks-sdk-go#993

## Tests
<!-- 
How is this tested? Please see the checklist below and also describe any
other relevant tests
-->

- [x] `make test` run locally
- [x] `make fmt` applied
- [ ] relevant integration tests applied

Author: vsamoilov

tests/test_jobs.py

@@ -0,0 +1,100 @@
+from databricks.sdk import WorkspaceClient
+
+
+# Test cases below are checking that we pinned API 2.1 for certain endpoints, DO NOT REMOVE OR CHANGE THEM. https://databricks.atlassian.net/browse/JOBS-19298
+def test_jobs_create(config, requests_mock):
+    requests_mock.post("http://localhost/api/2.1/jobs/create",
+                       request_headers={
+                           'Accept': 'application/json',
+                           'Content-Type': 'application/json',
+                       },
+                       text="null",
+                       )
+
+    w = WorkspaceClient(config=config)
+    w.jobs.create()
+
+    assert requests_mock.call_count == 1
+    assert requests_mock.called
+
+
+def test_jobs_update(config, requests_mock):
+    requests_mock.post("http://localhost/api/2.1/jobs/update",
+                       request_headers={
+                           'Accept': 'application/json',
+                           'Content-Type': 'application/json',
+                       },
+                       text="null",
+                       )
+
+    w = WorkspaceClient(config=config)
+    w.jobs.update(job_id="job_id")
+
+    assert requests_mock.call_count == 1
+    assert requests_mock.called
+
+
+def test_jobs_list(config, requests_mock):
+    requests_mock.get("http://localhost/api/2.1/jobs/list",
+                      request_headers={
+                          'Accept': 'application/json',
+                      },
+                      text="null",
+                      )
+
+    w = WorkspaceClient(config=config)
+    for _ in w.jobs.list():
+        pass
+
+    assert requests_mock.call_count == 1
+    assert requests_mock.called
+
+
+def test_jobs_get(config, requests_mock):
+    requests_mock.get("http://localhost/api/2.1/jobs/get",
+                      request_headers={
+                          'Accept': 'application/json',
+                      },
+                      text="null",
+                      )
+
+    w = WorkspaceClient(config=config)
+    w.jobs.get(job_id="job_id")
+
+    assert requests_mock.call_count == 1
+    assert requests_mock.called
+
+
+def test_jobs_reset(config, requests_mock):
+    requests_mock.post("http://localhost/api/2.1/jobs/reset",
+                       request_headers={
+                           'Accept': 'application/json',
+                           'Content-Type': 'application/json',
+                       },
+                       text="null",
+                       )
+
+    w = WorkspaceClient(config=config)
+    w.jobs.reset(job_id="job_id", new_settings=None)
+
+    assert requests_mock.call_count == 1
+    assert requests_mock.called
+
+
+def test_jobs_runs_list(config, requests_mock):
+    requests_mock.get("http://localhost/api/2.1/jobs/runs/list",
+                      request_headers={
+                          'Accept': 'application/json',
+                      },
+                      text="null",
+                      )
+
+    w = WorkspaceClient(config=config)
+    for _ in w.jobs.list_runs(job_id="job_id"):
+        pass
+
+    assert requests_mock.call_count == 1
+    assert requests_mock.called
+
+
+# End of test cases for API 2.1 pinning