[CI] Check Spec loading

[MarcusDenker]

Bug description
One PR showed a load problem (this is #16928 )

MetacelloNotification: Loaded -> Spec2-Commander2 --- github://pharo-spec/Spec:Pharo13/src(4973383)
MetacelloNotification: Loaded -> Spec2-ListView --- github://pharo-spec/Spec:Pharo13/src(4973383)
Error: Package UNKNOWN depends on the following classes:
  SpMorphicListAdapter
  SpMorphicListDataSource
You must resolve these dependencies before you will be able to load these definitions: 
  SpMorphicListViewAdapter
  SpMorphicListViewAdapter>>#buildWidget
  SpMorphicListViewAdapter>>#newDataSource
  SpMorphicListViewAdapter>>#newTableWith:
  SpMorphicListViewDataSource
  SpMorphicListViewDataSource>>#cellColumn:row:

It is not yet clear if this is a real problem (after external pagages get changes, only the next random build of pharo will get those changes).

There where two PRs merged in spec:

pharo-spec/Spec#1573
pharo-spec/Spec#1565

[jecisc]

I hope to fix it with this: pharo-spec/Spec#1575

[jecisc]

I fixed the error reported but now there is another one. I'll check it

[jecisc]

MetacelloNotification: Loaded -> Spec2-Commander2 --- github://pharo-spec/Spec:Pharo13/src(90dceb7)
MetacelloNotification: Loaded -> Spec2-ListView --- github://pharo-spec/Spec:Pharo13/src(90dceb7)
�[31mError: Package UNKNOWN depends on the following classes:
  SpAbstractListPresenterTest
You must resolve these dependencies before you will be able to load these definitions: 
  SpEasyListViewPresenterTest
  SpEasyListViewPresenterTest>>#classToTest
  SpEasyListViewPresenterTest>>#initializeTestedInstance
  SpEasyListViewPresenterTest>>#testHideHeaderTitleUnsetsTitle
  SpEasyListViewPresenterTest>>#testIconFor
  SpEasyListViewPresenterTest>>#testSetHeaderTitleHasTitle
  SpEasyListViewPresenterTest>>#testSetHeaderTitleSetsTitle
  SpEasyListViewPresenterTest>>#testWhenIconsChangedDo
  SpListViewPresenterTest
  SpListViewPresenterTest>>#classToTest
  SpListViewPresenterTest>>#initializeTestedInstance
  SpListViewPresenterTest>>#tearDown

�[0mMCPackageLoader(Object)>>notify:
MCPackageLoader>>warnAboutDependencies
MCPackageLoader>>validate

[jecisc]

pharo-spec/Spec#1576

[jecisc]

It's fixed