tests: stop using private ops classes #967

# to view logs

Job	Run time
PR / Check against ignorelist	4s
PR / Quality Checks / Check the CHARMHUB_TOKEN secret	1s
PR / Quality Checks / Linting / Lint	14s
PR / Quality Checks / Inclusive naming / check	9s
PR / Quality Checks / Scenario Tests / Scenario tests	25s
PR / Quality Checks / Static Analysis / Static Analysis of Charm	34s
PR / Quality Checks / Static Analysis / Static Analysis of Libs	19s
PR / Quality Checks / Unit Tests / Unit tests	53s
PR / Quality Checks / Check libraries	0s
PR / Quality Checks / CodeQL analysis / Analyze (python)	1m 19s
PR / Quality Checks / Integration Tests / Integration Tests	1h 23m 56s
	1h 27m 54s

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