[Term Entry] Java Math Methods: `.cbrt()`

[Dusch4593]

Reason/inspiration (optional)

Under java/concepts/math-methods/terms/, create a new term entry for the Math.cbrt() Java method.

• In the terms/ folder, make a new folder called cbrt/
• Inside the cbrt/ folder, create a new markdown file called cbrt.md
• Inside the file, be sure to include a "Syntax" section with a ```pseudo code snippet.
• Also make sure to include an "Example" section with a ```java code snippet.

Please refer to the entry templates, content standards, and markdown style guide when working on the PR for this issue.

Entry Type (select all that apply)

New Term for Existing Concept Entry

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