test: remove redis action from macos

[Panaetius]

removes redis action from macos test since it only works on linux. This test doesn't use redis anyways so everything passed when I tested

[coveralls]

Pull Request Test Coverage Report for Build 6483440020

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.02%) to 85.498%

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Files with Coverage Reduction	New Missed Lines	%
renku/core/dataset/providers/dataverse.py	1	64.76%
renku/ui/cli/init.py	1	96.9%
renku/ui/cli/service.py	1	74.07%
renku/command/rollback.py	2	78.7%

Totals
Change from base Build 6479621444:	0.02%
Covered Lines:	26276
Relevant Lines:	30733

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💛 - Coveralls