Fix test_resample index dtype checking for pandas 2.2

[mroeschke]

Description

I think this got unintentionally fixed in pandas 2.2, but pandas.testing.assert_series_equal will be strict about checking a Series's Index's dtype for date-likes. Since pandas always returns ns in resample and cudf tries to match the resolution frequency (IMO the better behavior), need to specify check_index=False in pandas 2.2

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[galipremsagar]

/merge