TST/CLN: some RunTimeWarnings
after #13145 some RunTimeWarnings remain in the codebase. We should look at these and silence (using `np.errstate`), or fix if we are testing something odd. (running the full test suite will show these; I have extracted them, some are showing a level too low in the stack).
- [ ] `pandas/pandas/tseries/index.py:526: RuntimeWarning: overflow encountered in long_scalars return lambda x: Timestamp(x, freq=self.offset, tz=self.tz)`
- [ ] `pandas/pandas/tseries/tests/test_tslib.py:453: RuntimeWarning: overflow encountered in long_scalar self.assertIs(ts.tz_localize(tz, errors='coerce'),`
- [ ] `pandas/pandas/core/internals.py:2341: RuntimeWarning: overflow encountered in long_scalar f = lambda x: lib.Timestamp(x, tz=self.values.tz)`
- [ ] `pandas/pandas/core/internals.py:4753: ComplexWarning: Casting complex values to real discards the imaginary part nn_at = nn.astype(v.dtype)`
- [ ] `pandas/pandas/tests/test_algos.py:735: RuntimeWarning: overflow encountered in long_scalars np.array([pd.Timestamp(d, tz='US/Eastern') for d in dt]),`
- [ ] `pandas/pandas/core/ops.py:650: RuntimeWarning: invalid value encountered in double_scalars lambda x: op(x, rvalues))`
