chore(sdk): fix use of invalid escape sequence in tests

[connor-mccarthy]

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[google-oss-prow]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[connor-mccarthy]

/assign @chensun

[connor-mccarthy]

/retest

[google-oss-prow]

@connor-mccarthy: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
kfp-kubernetes-execution-tests	26e0c4d	link	false	/test kfp-kubernetes-execution-tests

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[chensun]

/lgtm

[google-oss-prow]

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This pull-request has been approved by: chensun

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