remove: remove stats/tools

This commit removes the entire `@stdlib/stats/tools` namespace and
its sub-namespaces. The individual packages have been moved to other
namespaces as part of a package migration.

BREAKING CHANGE: remove `stats/tools`

To migrate, users should perform the following migrations:

- `@stdlib/tools/reduce/unary-strided-dispatch` should become
  `@stdlib/ndarray/base/unary-reduce-strided1d-dispatch`
- `@stdlib/tools/reduce/unary-strided-dispatch-factory` should become
  `@stdlib/ndarray/base/unary-reduce-strided1d-dispatch-factory`
- `@stdlib/tools/cumulative/unary-strided-dispatch` should become
  `@stdlib/ndarray/base/unary-strided1d-dispatch`
- `@stdlib/tools/cumulative/unary-strided-dispatch-factory` should become
  `@stdlib/ndarray/base/unary-strided1d-dispatch-factory`

For the `stats/tools`, `stats/tools/reduce`, and `stats/tools/cumulative`,
the migration path is to depend on the previously exported symbols
directly by importing the exact package needed.

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
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    status: passed
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---

Author: kgryte