Increase the usage of augmented assignment statements

:eyes: Some source code analysis tools can help to find opportunities for improving software components.
:thought_balloon: I propose to [increase the usage of augmented assignment statements](https://docs.python.org/3/reference/simple_stmts.html#augmented-assignment-statements "Augmented assignment statements") accordingly.

Would you like to integrate anything from a transformation result which can be generated by a command like the following?
(:point_right: Please check also for questionable change suggestions because of an evolving search pattern.)
```
[Markus_Elfring@fedora lokal]$ perl -p -i.orig -0777 -e 's/^(?\s+)(?\S+)\s*=\s*\k\s*(?[+\-%&|^@]|\*\*?|\/\/?|<<|>>)/$+{indentation}$+{target} $+{operator}=/gm' $(find ~/Projekte/manim/lokal -name '*.py')
```

該 issue 建議在 Python 檔案中使用 Perl one-liner 查找並取代類似 'x = x + y' 為 'x += y' 的模式。首先，從 Python 文件中理解增強賦值（augmented assignment）語法。接著，在儲存庫中的一小部分 .py 檔案上測試該 Perl 指令，查看它會做出哪些更改。請仔細檢查 diff，確保沒有非預期的修改，因為模式可能會演進。最後，選擇性地套用這些更改，並透過執行現有測試來驗證程式碼仍然正常運作。

由索引模型根據 Issue 內容生成。