feat(build): Improve helm toolchain

This changes how helm is installed as part of the deployment scripts.
Instead of downloading helm via go, we instead download it via the
github releases and use the prebuilt binary. We also verify the hash of
the binary we download.

cmake/FindHelm.cmake

@@ -1,10 +1,44 @@
-include(GolangUtils)
+set(HELM_VERSION "v3.15.1")
+if (WIN32) 
+  set(HELM_OS "windows")
+  set(HELM_ARCH "amd64") # arm not supported on windows
+  set(HELM_HASH "8ebe6d353f0fbc7e51861a676ba1c14af9efb3443ae2c78eb91946a756b93a9a")
+elseif (APPLE)
+  set(HELM_OS "darwin")
+  if("${CMAKE_HOST_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
+    set(HELM_ARCH "amd64")
+    set(HELM_HASH "5fdc60e090d183113f9fa0ae9dd9d12f0c1462b9ded286370f84e340f84bd676")
+  elseif("${CMAKE_HOST_SYSTEM_PROCESSOR}" STREQUAL "arm64")
+    set(HELM_ARCH "arm64")
+    set(HELM_HASH "4b04ede5ab9bb226c9b198c94ce12818f0b0e302193defd66970b45fc341f6e7")
+  else()
+    message(FATAL "Unrecognized system architecture for MacOS: ${CMAKE_HOST_SYSTEM_PROCESSOR}")
+  endif()
+elseif (UNIX)
+  set(HELM_OS "linux")
+  if("${CMAKE_HOST_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
+    set(HELM_ARCH "amd64")
+    set(HELM_HASH "7b20e7791c04ea71e7fe0cbe11f1a8be4a55a692898b57d9db28f3b0c1d52f11")
+  elseif("${CMAKE_HOST_SYSTEM_PROCESSOR}" STREQUAL "arm64")
+    set(HELM_ARCH "arm64")
+    set(HELM_HASH "b4c5519b18f01dd2441f5e09497913dc1da1a1eec209033ae792a8d45b9e0e86")
+  else()
+    message(FATAL "Unrecognized system architecture for Unix: ${CMAKE_HOST_SYSTEM_PROCESSOR}")
+  endif()
+endif()
 
-set(HELM_EXECUTABLE ${GO_BIN_DIR}/helm CACHE INTERNAL "Path to the local helm tooling")
-SET(HELM_VERSION "v3.15.0")
-go_install(
-  OUTPUT ${HELM_EXECUTABLE}
-  PACKAGE "helm.sh/helm/v3/cmd/helm"
-  VERSION ${HELM_VERSION}
+set(HELM_TEMP_DIR ${CMAKE_BINARY_DIR}/tools/temp/helm)
+set(HELM_TEMP_ARCHIVE ${HELM_TEMP_DIR}/helm.tar.gz)
+file(MAKE_DIRECTORY ${HELM_TEMP_DIR})
+if(NOT EXISTS ${HELM_TEMP_ARCHIVE})
+  message(STATUS "Downloading helm ${HELM_VERSION} (${HELM_OS}/${HELM_ARCH})")
+endif()
+file(DOWNLOAD "https://get.helm.sh/helm-${HELM_VERSION}-${HELM_OS}-${HELM_ARCH}.tar.gz" ${HELM_TEMP_ARCHIVE}
+  TIMEOUT 30
+  TLS_VERIFY ON
+  EXPECTED_HASH "SHA256=${HELM_HASH}"
 )
-
+file(ARCHIVE_EXTRACT INPUT ${HELM_TEMP_ARCHIVE}
+  DESTINATION ${HELM_TEMP_DIR}
+)
+set(HELM_EXECUTABLE "${HELM_TEMP_DIR}/${HELM_OS}-${HELM_ARCH}/helm" CACHE INTERNAL "Path to the local helm tooling")