- lib557: suppress `-Wformat-overflow` warning in source.
Fixes:
```
lib557.c: In function ‘test_float_formatting’:
lib557.c:1408:37: error: ‘%*f’ directive output of 2147483648 bytes exceeds ‘INT_MAX’ [-Werror=format-overflow=]
1408 | curl_msnprintf(buf, sizeof(buf), "%*f", INT_MIN, 9.1);
| ^~~
lib557.c:1408:3: note: ‘curl_msnprintf’ output 2147483649 bytes
1408 | curl_msnprintf(buf, sizeof(buf), "%*f", INT_MIN, 9.1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Ref: https://app.circleci.com/pipelines/github/curl/curl/10226/workflows/87642ee9-cda6-4916-8206-c82aac5f595e/jobs/107669?invite=true#step-106-40996_46
The root cause of why this option gets enabled remains undiscovered.
Reported-by: Daniel Stenberg
Fixes#15008
Follow-up to 71cf0d1fca#14772
- build: drop `-Wno-format-overflow` from picky warning list.
These options only get used with picky warnings enabled.
Follow-up to 145f87b9e8#14598
- unit1652: suppress in source (and not rely on picky warnings anymore.)
Closes#15012
4619b4103b