ci: purge after flexsuite
ci: purge after flexsuite

If we don't the mgr tests cannot verify the osd creation and will fail
with:

```
--- FAIL: TestCephMgrSuite (169.32s)
    --- FAIL: TestCephMgrSuite/TestCreateOSD (1.65s)
        ceph_mgr_test.go:217:
            	Error Trace:	ceph_mgr_test.go:217
            	Error:      	Should not be: ""
            	Test:       	TestCephMgrSuite/TestCreateOSD
            	Messages:   	No devices available to create test OSD
        ceph_mgr_test.go:218:
            	Error Trace:	ceph_mgr_test.go:218
            	Error:      	Should not be: ""
            	Test:       	TestCephMgrSuite/TestCreateOSD
            	Messages:   	No nodes available to create test OSD
```

Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

rook/nfs,rook/rook,rook/nfs,rook/rook,rook/rook,rook/nfs,rook/rook,rook/rook