[Fix] Warning filter in fluctuating LB test

The fluctuating LB test used an old syntax of the pytest module to check for warnings. This now triggers an error and lets the test fail. With this MR new syntax suggested by the pytest package is used.

Furthermore, fix of some warnings

requested review from @da15siwa

assigned to @holzer

added 1 commit

• 00e23615 - Remove warning

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added 1 commit

• 010f0bb9 - Try to remove conftest warnings

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added 1 commit

• 2538a812 - Try to remove conftest warnings

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merged

mentioned in commit 2d71e942