TST: test error fixes with pandas 2.0

[hongyeehh]

Pandas released v2.0 which causes some errors in our test functions:

• append function deprecated and shall be replaced by concat:

Removed deprecated Series.append(), DataFrame.append(), use concat() instead (GH35407)

• More flexible dtypes for pandas.index, link

In addition, infer_datetime_format argument is depricated:

Deprecated argument infer_datetime_format in to_datetime() and read_csv(), as a strict version of it is now the default (GH48621)

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (bbc8331) 98.19% compared to head (5559c89) 98.19%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #470   +/-   ##
=======================================
  Coverage   98.19%   98.19%           
=======================================
  Files          39       39           
  Lines        1886     1888    +2     
  Branches      328      328           
=======================================
+ Hits         1852     1854    +2     
  Misses         13       13           
  Partials       21       21           

Impacted Files	Coverage Δ
trackintel/preprocessing/util.py	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[henrymartin1]

Thanks for the fix!