Make use of GCC 14 features

[laurynas-biveinis]

• Enable new GCC 14 warnings
• Annotate source with null_terminated_string_arg() attribute where applicable
• Add more attribute-like macros to .clang-format

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.17%. Comparing base (7f4fb01) to head (40174f0).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #577 +/- ## ======================================= Coverage 99.17% 99.17% ======================================= Files 21 21 Lines 2186 2186 ======================================= Hits 2168 2168 Misses 18 18 ``` | [Flag](https://app.codecov.io/gh/laurynas-biveinis/unodb/pull/577/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Laurynas+Biveinis) | Coverage Δ | | |---|---|---| | [Debug](https://app.codecov.io/gh/laurynas-biveinis/unodb/pull/577/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Laurynas+Biveinis) | `99.08% <ø> (ø)` | | | [Release](https://app.codecov.io/gh/laurynas-biveinis/unodb/pull/577/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Laurynas+Biveinis) | `97.92% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Laurynas+Biveinis#carryforward-flags-in-the-pull-request-comment) to find out more.

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