CLN: ASV attrs_caching benchmark
- Added `np.random.seed(1234)` in setup classes where random data is created xref #8144

- Ran flake 8 and replaced star imports (with pep8 in mind, I think we should avoid `from .pandas_vb_common import *`) 

```
$asv run -q -b ^attrs_caching
[ 33.33%] ··· Running attrs_caching.CacheReadonly.time_cache_readonly                                                                   9.12μs
[ 66.67%] ··· Running attrs_caching.DataFrameAttributes.time_get_index                                                                  14.5μs
[100.00%] ··· Running attrs_caching.DataFrameAttributes.time_set_index                                                                  27.3μs
```
