[df] Improve warning message when lazy Snapshot is not triggered #15252

Job	Run time
Windows 10 x64 Release	1h 0m 26s
fedora40 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	35m 56s
Windows 10 x86 Release	1h 46m 22s
mac13 ARM64 LLVM_ENABLE_ASSERTIONS=On, builtin_zlib=ON	24m 28s
fedora41 LLVM_ENABLE_ASSERTIONS=On	31m 3s
mac14 X64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	1h 3m 36s
alma8 LLVM_ENABLE_ASSERTIONS=On	44m 17s
Upload Event Payload	2s
mac15 ARM64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	28m 20s
alma9 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 31m 10s
ubuntu22 imt=Off, LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 34m 37s
mac-beta ARM64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	40m 0s
ubuntu2404 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 50m 54s
ubuntu2410 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 11m 37s
debian125 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	28m 35s
alma9 modules_off runtime_cxxmodules=Off	33m 10s
alma9 march_native CMAKE_BUILD_TYPE=RelWithDebInfo, CMAKE_CXX_FLAGS=-march=native, CMAKE_C_FLAGS=-march=native, fortran=OFF	23m 19s
alma9-clang clang LLVM_ENABLE_ASSERTIONS=On, CMAKE_C_COMPILER=clang, CMAKE_CXX_COMPILER=clang++	42m 14s
	15h 30m 6s

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