Fix octopus fixture paths on windows

[sarah-witt]

What does this PR do?

fixes fixture paths so they are compatible with windows filesystems

Motivation

breaking windows builds

Notes

validation fix is here: #19432

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Add the qa/skip-qa label if the PR doesn't need to be tested during QA.
• If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.84%. Comparing base (33a15dd) to head (adb0859).
Report is 4 commits behind head on master.

Additional details and impacted files

Flag	Coverage Δ
activemq	?
cassandra	?
confluent_platform	?
hive	?
hivemq	?
hudi	?
ignite	?
jboss_wildfly	?
kafka	?
octopus_deploy	99.16% <100.00%> (?)
presto	?
solr	?

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