Starting with gcc 16, libstdc++ links to libatomic. Add to whitelist.

$ ldd /lib64/libstdc++.so.6
	linux-vdso.so.1 (0x00007f3cb4c13000)
	libm.so.6 => /lib64/libm.so.6 (0x00007f3cb4afc000)
	libatomic.so.1 => /lib64/libatomic.so.1 (0x00007f3cb4af1000)
	libc.so.6 => /lib64/libc.so.6 (0x00007f3cb460d000)
	libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f3cb4ac5000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f3cb4c15000)

Author: ellert

bindings/pyroot/pythonizations/test/import_load_libs.py

@@ -77,6 +77,7 @@ class ImportLoadLibs(unittest.TestCase):
         "ld.*",
         "libffi",
         "libgcc_s",
+        "libatomic",
         # AddressSanitizer runtime and ROOT configuration
         "libclang_rt.asan-.*",
         "libROOTSanitizerConfig",