software/re6stnet,slapos-testing: fix re6stnet develop

Because re6stnet now uses hatchling, it needs some packages installed
for develop step.

ref: re6stnet@88a883db
6 jobs for fix/re6stnet-editable-install-hatch in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.Eggs.UnitTest-TestRunner1.Python2

00:23:58

passed SlapOS.Eggs.UnitTest-TestRunner1.Python3

00:29:05

canceled SlapOS.SoftwareReleases.IntegrationTest-TestRunner1

10:41:01

canceled SlapOS.Theia.ResilienceTest-ForTestRunner1-Gitlab

02:52:57

canceled SlapOS.Theia.ResilienceTest-ForTestRunner1-Peertube

02:16:08

passed SlapOS.Eggs.UnitTest-TestRunner1.Python2

00:25:18