fix(core): remove the killed execution from the map after killing it

[loicmathieu]

This should be safe to purge the map at this stage. And should fix a small memory leak when killing task often.

[loicmathieu]

@tchiotludo I think this one should also be merged as it avoid a slight memory leak on killed execution.

[sonarqubecloud[bot]]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud