[patch] Don't let attribute injection work for private variables.

[liamhuber]

For compatibility with iPython, which runs around asking for _ipython_canary_method_should_not_exist_ left, right, and center.

Closes #253

[github-actions[bot]]

:point_left: Launch a binder notebook on branch _pyiron/pyiron_workflow/patch_ipython_injectionbug

[codacy-production[bot]]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
:white_check_mark: +0.01% (target: -1.00%)	:white_check_mark: 100.00%

Coverage variation details

| | Coverable lines | Covered lines | Coverage | | ------------- | ------------- | ------------- | ------------- | | Common ancestor commit (34b5335637077691001011caaa13e00ce396b729) | 3282 | 2868 | 87.39% | | | Head commit (b96ab3d86be163359f25faa570bc6c9db87b4715) | 3284 (+2) | 2870 (+2) | 87.39% (**+0.01%**) | **Coverage variation** is the difference between the coverage for the head and common ancestor commits of the pull request branch: ` - `

Diff coverage details

| | Coverable lines | Covered lines | Diff coverage | | ------------- | ------------- | ------------- | ------------- | | Pull request (#254) | 2 | 2 | **100.00%** | **Diff coverage** is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: `/ * 100%`

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