feat: use debug_assertions instead of custom feature

[de-sh]

Fixes #XXXX.

Description

We don't need a custom feature, https://doc.rust-lang.org/reference/conditional-compilation.html#debug_assertions

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This PR has:

• been tested to ensure log ingestion and log query works.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added documentation for new or modified features or behaviors.

[coveralls]

Pull Request Test Coverage Report for Build 12863585408

Details

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 12.714%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/handlers/http/mod.rs	0	1	0.0%

Totals
Change from base Build 12855418418:	0.0%
Covered Lines:	2459
Relevant Lines:	19341

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💛 - Coveralls

[nitisht]

Does this mean the debug section is enabled when building without --release flag?

Also can you confirm we don't need a change in the Dockerfile here: https://github.com/parseablehq/parseable/blob/main/Dockerfile.debug

[nitisht]

Added a comment

[de-sh]

We have made that change @nitisht