Use OIIO cmake logic to find robinmap #53

Job	Run time
macos-13 C++17 py3.11 MacOS-13 llvm17	5m 1s
Ubuntu Debug gcc7/C++14 llvm9 py2.7 oiio2.3 exr2.4 sse4 exr2.4	2m 8s
macos-14 C++17 py3.11 MacOS-14-ARM llvm17	5m 52s
Ubuntu gcc10/C++17 llvm10 oiio-release exr2.5 avx2	1m 42s
VFX2019 gcc6/C++14 llvm9 py2.7 exr2.4 oiio2.3 sse2	7m 20s
Ubuntu latest releases gcc11/C++17 llvm16 exr3.2 py3.9 avx2 batch-b16avx512	14m 55s
VFX2019 clang9/C++14 llvm9 oiio-release avx2 exr2.4 py2.7	7m 43s
Ubuntu bleeding edge gcc12/C++17 llvm17 oiio/ocio/exr/pybind-master py3.10 avx2 batch-b16avx512	18m 50s
VFX2020 gcc6/C++14 llvm10 py3.7 exr2.4 oiio2.2 sse4	6m 18s
Ubuntu clang14/C++17 llvm14 exr3.1 py3.8 avx2 batch-b16avx512	15m 42s
VFX2021 gcc9/C++17 llvm11 py3.7 exr2.5 oiio2.3 avx2 batch-b8avx2	8m 30s
Ubuntu clang-format	1m 57s
VFX2022 gcc9/C++17 llvm13 py3.9 exr3.1 oiio-rel avx2	8m 12s
VFX2022 clang12/C++17 llvm12 oiio-master exr3.1 py3.9 avx2 batch-avx512	11m 56s
VFX2022 icc/C++17 llvm14 py3.9 exr3.1 oiio-master avx2	19m 8s
VFX2022 icx/C++17 llvm14 py3.9 exr3.1 oiio2.3 avx2	11m 44s
VFX2023 gcc11/C++17 llvm15 py3.10 exr3.1 oiio-rel avx2	10m 2s
VFX2023 GPU Cuda11 gcc11/C++17 llvm15 py3.10 exr3.1 OIIO-master avx2	7m 35s
VFX2019 oldest everything gcc6/C++14 llvm9 py2.7 oiio2.3 no-simd exr2.4	7m 16s
VFX2022 sanitizers	7m 38s
VFX2023 abi check	7m 2s
	3h 6m 31s

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