reconcile: Set observed gen only when conditions exist

[darkowlzz]

The observed generation must be set only when actual observation is
made. When an actual observation is made, some conditions are set on the
object. Introduce a helper function
addPatchOptionWithStatusObservedGeneration() to set the patcher option
WithStatusObservedGeneration only when there's any condition in the
status.

Updates the existing tests that depended on this behavior.

This fixes the issue where the observed generation is set by the patcher
when a reconciler does an early return for setting the finalizers only.
With this, the observed generation will be updated only when some
observations are made on the object based on the usual rules of success
result, no error, ignore error and stalled condition.

After finalizer setting reconcile -

Before this change:

status:
  observedGeneration: 1

After this change:

status:
  observedGeneration: -1

Ref: fluxcd/flux2#2736

[darkowlzz]

Looks like it's minio again:

*** Test killed with quit: ran too long (11m0s).
FAIL	github.com/fluxcd/source-controller/pkg/minio	660.006s

[stefanprodan]

IMO this is a regression bug fix not an enhancement

[darkowlzz]

I haven't verified that it fixes the CLI issue. Couldn't reproduce it locally by creating a GitRepo and Kustomization rapidly based on the example in https://github.com/fluxcd/flux2-multi-tenancy/blob/50ad87d14542a09249bfe761b441078f12b4053f/.github/workflows/e2e.yaml#L43 . Need to try it in flux2-multi-tenancy CI.
But the CLI code that fails, maybe https://github.com/fluxcd/flux2/blob/938f2570efb05f26ff83b7684f950389b7d3f60b/cmd/flux/create_source_helm.go#L245-L250 , doesn't use the status.observedGeneration, but Ready condition's observedGeneration.
I believe that's very different from what this change does and may not be directly related.

[hiddeco]

This is indeed a bug and not an enhancement as it was not working as intended, even if this would not pose an issue to the CLI.