Bug: build_src_flags has an impact on lib_deps

[omani]

$ pio --version
PlatformIO Core, version 6.1.19a2

see my #4667 (comment)

in particular this is the case for "-Wpedantic" set in build_src_flags

[omani]

more sources
https://community.platformio.org/t/silence-warnings-for-dependencies-external-libraries/33387/14
https://community.platformio.org/t/lib-ignore-vs-build-src-filter-the-latter-was-not-working-for-me/38868

platformio/platform-espressif32#1146

#4253

any maybe related:
#4578