[12.x] Fix $model->incrementEach() and decrementEach() to scope query to model's primary key

[sumaiazaman]

Description

Fixes #57262

When calling $model->incrementEach() or $model->decrementEach() on an existing Eloquent model instance, the call was forwarded via __call() to the query builder without a WHERE clause scoped to the model's primary key. This caused ALL rows in the table to be updated instead of just the specific model instance — a serious data corruption bug.

// Correctly scoped to $model — only updates this record
$model->increment('number');

// BUG: updates ALL records in the table 😢
$model->incrementEach([
    'number' => 1,
    'another_number' => 1,
]);

Root Cause

increment() and decrement() are listed in __call() and dispatched to the model's own increment() and decrement() are listed in __ctoincrement()anddecrentincrement()decrementEach() were **not** in that list, so they fell thincrement()anddecrement()are listed in__call()and dispatched to the model's ownincremeusincrement() and dncrincrementanddecrementEach()protected methods onModel, mirroring the existing increment()/decrement()` pattern.

• Added a shared incrementOrDecrementEach() helper that uses setKeysForSaveQuery() to scope the update to the model's primary key, fires updating/updated model events, and syncs the model's in-memory attributes after the update.
• Regist- Registh - Regist- Registh - Regist- Registh - Regist- Registh - Reng forwarded to the query builder.

Tests

Added two unit tests to DatabaseEloquentModelTest:

• - - - - - - hO- - - - - - - hO- yToModelKey -------------mentEachOnExistingModelScopesQueryToModelKey

Both verify that WHERE id = ? is applied ande model's in-memory attributes are updated correctly.