Replace assert.deepEqual with assert.deepStrictEqual

[ijlee2]

Description

While documenting @codemod-utils/tests, I learned that assert.deepEqual is an alias of assert.deepStrictEqual and the latter should be used to avoid unexpected results.

Strict assertion mode

An alias of assert.deepStrictEqual().

Legacy assertion mode

Stability: 3 - Legacy: Use assert.deepStrictEqual() instead.

Tests for deep equality between the actual and expected parameters. Consider using assert.deepStrictEqual() instead. assert.deepEqual() can have surprising results.

https://nodejs.org/api/assert.html#assertdeepequalactual-expected-message