migrate test-infra to testify for session/pessimistic_test.go

[tisonkun]

No description provided.

[hawkingrei]

/assign

[tisonkun]

cc @hawkingrei @bb7133 @tiancaiamao

So far, check_dev_2 use -check.f and -check.exclude to switch between pessimistic tests and other session tests.

However, as we're migrating from go-check (pingcap/check) to testify, these flags doesn't work anymore and we'd better using a new approach to achieve the goal.

I propose that we:

1. Introduce a new flag named runPessimisticTest in the codebase.
2. Pass the flag accordingly in the test script linked above.
3. Switch behavior in the codebase.
4. Stop passing -check.f and -check.exclude flags.

In this way, we're decouple with go-check's test filter mechanism.

[tisonkun]

Another proposal is that we move these real tikv dependent tests to a new directory so that we don't mix up unit tests and those, as well as avoiding pushing all real tikv dependent tests under "session" pkg.

[tisonkun]

Instead of modifying the CI pipeline, we can also handle those flag in code and thus decouple from CI changes.

[tisonkun]

FYI you can refer to this file changes for my idea. But session test is still too stateful to debug...I'm unsure whether I make the test cases migrated right.

https://github.com/pingcap/tidb/pull/34072/files#diff-e951bea80fdefa1841c9403b93301ac5a9d68fc7e623538d2ccfddd159056191

[tisonkun]

I'm trying to running these tests with GitHub Actions so that I can handle the environment better.