[BEAM-8565] Update .test-infra/jenkins/README with missing entries an…

[sunjincheng121]

Currently the following tests are missing in the .test-infra/jenkins/README:

 beam_PreCommit_BeamSQL_ZetaSQL
 beam_PostCommit_CrossLanguageValidatesRunner
 beam_PostCommit_Java11_Dataflow_Examples
 beam_PostCommit_Java11_Dataflow_Portability_Examples
 beam_PostCommit_PortableJar_Flink
 beam_PostCommit_Python_MongoDBIO_IT
 beam_PostCommit_Website_Test
 beam_PerformanceTests_KafkaIOIT
 beam_PerformanceTests_MongoDBIOIT
 beam_LoadTests_Python_ParDo_Flink_Batch

The following tests are duplicate:

 beam_PreCommit_Go
 beam_PreCommit_JavaPortabilityApi

The trigger command for the following items are wrong:

 beam_PreCommit_Java_Examples_Dataflow
 beam_PreCommit_Portable_Python
 beam_PreCommit_Python2_PVR_Flink
 beam_PerformanceTests_TFRecordIOIT

This PR will fix those issues.

Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---		---	---
Java
Python		---			---	---
XLang	---	---	---		---	---	---

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website
Non-portable
Portable	---		---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

[sunjincheng121]

R: @mxm

[mxm]

Great work @sunjincheng121. Thank you.

[sunjincheng121]

Great thanks for the quick merging. @mxm