[OpenFileManagerWindowJob] Fix crash when falling back to KRunStrategy
createKRunStrategy replaces the current strategy, which is then destroyed. We are still in that strategy's code though, causing a use-after-free crash.
To avoid this reshuffle the code so that the Job, not the Strategy invokes the fallback
BUG: 486494 SENTRY: PLASMA-WORKSPACE-2WM SENTRY: KMAIL-21 SENTRY: SYSTEMSETTINGS-50 SENTRY: KATE-5Z SENTRY: FALLTHROUGH-4DF SENTRY: DOLPHIN-1QT SENTRY: OKULAR-8G SENTRY: SPECTACLE-14