pd.Timedelta() cannot process offset alias T while pd.infer_freq() return this format. #21762
Description
Code Sample, a copy-pastable example if possible
import pandas as pd
series = pd.Series([1, 2, 3], pd.date_range('201701010000', '201701010030', freq='15min'))
print(pd.infer_freq(series.index))
# Error
pd.Timedelta(pd.infer_freq(series.index))
# While this works
pd.Timedelta(series.index.freq)Problem description
pd.Timedelta constructor works with e.g. '15min' but not with '15T',
while pd.infer_freq() returns '15T' and pd.Series.index.freq returns '15min'.
This leads to errors.
Expected Output
Same behaviour of pd.Timedelta() for 'min' and 'T' offset alias or deprecation of 'T' as an offset alias.