🚀 Add event filtering to the Workspace controller

[arybolovlev]

Description

This PR adds event filtering to the Workspace controller in order to reduce the number of unnecessary reconciliations, i.e. trigger reconciliation only when CR .spec gets updated. This behavior matches with other controllers.

Usage Example

N/A.

Release Note

Release note for CHANGELOG:

`Workspace`: add event filtering to reduce the number of unnecessary reconciliations.

References

N/A.

Community Note

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