Detect if a Mac and fail gracefully

[ross-p-smith]

This feature does not install on a Mac. detect that it is a mac in the devcontainer-features-install.sh output a message and fail gracefully. Without this, the extension cant be included in repositories as devcontainers should be agnostic

RUN --mount=type=bind,from=dev_containers_feature_content_source,source=azure-functions-core-tools_4,target=/tmp/build-features-src/azure-functions-core-tools_4
71 | >>> cp -ar /tmp/build-features-src/azure-functions-core-tools_4 /tmp/dev-container-features
72 | >>> && chmod -R 0755 /tmp/dev-container-features/azure-functions-core-tools_4
73 | >>> && cd /tmp/dev-container-features/azure-functions-core-tools_4
74 | >>> && chmod +x ./devcontainer-features-install.sh
75 | >>> && ./devcontainer-features-install.sh
76 | >>> && rm -rf /tmp/dev-container-features/azure-functions-core-tools_4
77 |
[2024-03-20T05:33:53.606Z] ERROR: failed to solve: process "/bin/sh -c cp -ar /tmp/build-features-src/azure-functions-core-tools_4 /tmp/dev-container-features && chmod -R 0755 /tmp/dev-container-features/azure-functions-core-tools_4 && cd /tmp/dev-container-features/azure-functions-core-tools_4 && chmod +x ./devcontainer-features-install.sh && ./devcontainer-features-install.sh && rm -rf /tmp/dev-container-features/azure-functions-core-tools_4" did not complete successfully: exit code: 1

[jlaundry]

Hmmmm..... maybe a error message pointing users towards Azure/azure-functions-core-tools#3112

Unfortunately, the lack of arm64 packages has been ignored by Microsoft for almost 2 years now.... any chance you could please raise something internally @ross-p-smith ?