Set `cuda_compiler: "cuda-nvcc"` unconditionally

In the context of #7431, and, more importantly, #6967, we want to simplify the zip involving `cuda_compiler_version`. Since the compiler name changed between CUDA 11.x and CUDA 12.x, we so far needed to set https://github.com/conda-forge/conda-forge-pinning-feedstock/blob/9515b7b7dc04fc84a3af1b79171254efc3ea50dd/recipe/conda_build_config.yaml#L62-L65 and then zip `cuda_compiler` into the monster-zip. Now that we're dropping CUDA 11.8, we can simplify this and set `cuda_compiler` unconditionally (and thus remove it from the zip). Feedstocks that want to do something conditional on cuda or not can do ```yaml - foo # [cuda_compiler_version != "None"] ``` There's [currently](https://github.com/search?q=org%3Aconda-forge+path%3Arecipe%2Fmeta.yaml++%2Fcuda_compiler%5B%5E_%5D.*None%2F&type=code) 14 feedstocks that use `cuda_compiler` in selectors, but I've opened PRs to fix those, and then we can document that the above is the way to do it. * [x] https://github.com/conda-forge/carlsim6-feedstock/pull/7 * [ ] https://github.com/conda-forge/catboost-feedstock/pull/141 * [x] https://github.com/conda-forge/colmap-feedstock/pull/62 * [x] https://github.com/conda-forge/heat-feedstock/pull/60 * [ ] https://github.com/conda-forge/implicit-feedstock/pull/107 * [x] https://github.com/conda-forge/jaxlib-feedstock/pull/313 * [x] https://github.com/conda-forge/kaldi-feedstock/pull/59 * [x] https://github.com/conda-forge/openmm-feedstock/pull/156 * [x] https://github.com/conda-forge/openmpi-feedstock/pull/196 * [x] https://github.com/conda-forge/pixsfm-feedstock/pull/34 * [x] https://github.com/conda-forge/qiskit-aer-feedstock/pull/57 * [x] https://github.com/conda-forge/qsimcirq-feedstock/pull/28 * [ ] https://github.com/conda-forge/seekr2_openmm_plugin-feedstock/pull/24 * [ ] https://github.com/conda-forge/xgboost-feedstock/pull/243