tools: Fix pcp dependendency
tools: Fix pcp dependendency

cockpit-pcp requires pcp not just for its `%post` script, but for actual
operation. Don't allow uninstalling pcp with keeping cockpit-pcp
installed, as that confuses our on-demand installation.

martinpitt/cockpit,martinpitt/cockpit,mvollmer/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,mvollmer/cockpit,martinpitt/cockpit,cockpit-project/cockpit,mvollmer/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit,martinpitt/cockpit,martinpitt/cockpit