Updated the changelog for release 1.2.9

[jakobht]

What changed?
Updated changelog for release v1.2.9

Why?

How did you test it?

Potential risks

Release notes

Documentation Changes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 63.95%. Comparing base (03d54cf) to head (f2dea57).

Additional details and impacted files

see 8 files with indirect coverage changes

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[coveralls]

Pull Request Test Coverage Report for Build 018f358c-45c6-4dd1-aa73-50350ef7a113

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 43 unchanged lines in 13 files lost coverage.
• Overall coverage increased (+0.007%) to 68.114%

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Files with Coverage Reduction	New Missed Lines	%
common/task/weighted_round_robin_task_scheduler.go	2	89.05%
common/persistence/sql/sqlplugin/postgres/task.go	2	73.4%
service/matching/db.go	2	73.23%
service/history/task/transfer_active_task_executor.go	2	72.72%
common/util.go	2	91.78%
service/history/execution/mutable_state_util.go	2	78.52%
common/persistence/historyManager.go	2	66.67%
common/log/tag/tags.go	3	50.46%
common/task/fifo_task_scheduler.go	3	84.54%
service/history/task/fetcher.go	3	85.57%

Totals
Change from base Build 018f3564-86f5-4d1d-8b03-7be6def757b8:	0.007%
Covered Lines:	100013
Relevant Lines:	146831

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💛 - Coveralls