[RF] Fixes and performance improvements for `RooAbsArg::getParameters()` #22858

Job	Run time
Windows 10 x86 Release	1h 3m 43s
Windows 10 x64 Release	1h 13m 57s
mac14 X64 CMAKE_CXX_STANDARD=20	57m 29s
mac13 ARM64 builtin_zlib=ON	26m 6s
mac15 ARM64 CMAKE_CXX_STANDARD=23	32m 54s
Upload Event Payload	3s
mac-beta ARM64 CMAKE_CXX_STANDARD=23	45m 42s
alma8	31m 46s
fedora42 CMAKE_CXX_STANDARD=23	36m 45s
alma9 CMAKE_BUILD_TYPE=Debug	1h 9m 45s
alma10	41m 4s
fedora43 CMAKE_CXX_STANDARD=23	33m 12s
ubuntu22 imt=Off, CMAKE_BUILD_TYPE=Debug	1h 19m 12s
ubuntu2510 CMAKE_CXX_STANDARD=23	32m 52s
ubuntu2504 CMAKE_CXX_STANDARD=23	38m 45s
ubuntu2404 CMAKE_BUILD_TYPE=Debug	1h 33m 44s
alma9 modules_off runtime_cxxmodules=Off	27m 45s
alma9 arm64 CMAKE_BUILD_TYPE=RelWithDebInfo, builtin_zlib=ON, builtin_zstd=ON	51m 52s
debian125 CMAKE_CXX_STANDARD=20, dev=ON, CMAKE_CXX_FLAGS=-Wsuggest-override	34m 11s
alma10 clang Ninja CMAKE_C_COMPILER=clang, CMAKE_CXX_COMPILER=clang++	29m 57s
rawhide Fedora pydebug CMAKE_CXX_STANDARD=23	46m 26s
alma9 march_native CMAKE_BUILD_TYPE=RelWithDebInfo, CMAKE_CXX_FLAGS=-march=native, CMAKE_C_FLAGS=-march=native, builtin_zlib=ON, builtin_zstd=ON	31m 10s
	16h 18m 20s

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