Allow the user to select the transactionManager to use for TaskRepository

[cppwfs]

Currently Task Repositories use @transactional("springCloudTaskTransactionManager"). This should be replaced with a property i.e.
@transactional("${spring.cloud.task.transaction-manager:transactionManager}").
Also remove springCloudTaskTransactionManager bean.

This is for 3.0.0 release of SCT.

[cppwfs]

This was feature was added here: e458142

[GeniusMagnus]

Recently, I had to make use of the spring.cloud.task.transaction-manager property. On this occasion I observed that class SimpleTaskAutoConfiguration still instantiates a (useless) transaction manager which is not injected into the application context. This could be optimized.

[cppwfs]

@GeniusMagnus created issue to investigate.

[GeniusMagnus]

@cppwfs : Thank you! I actually thought nobody would be interested in my comment as this ticket was closed nearly two years ago. 😏

[cppwfs]

@GeniusMagnus thank you for reaching out! It is much appreciated!