Fix shellcheck errors

Author: jrflat

.github/workflows/scripts/install-and-build-with-sdk.sh

@@ -296,7 +296,8 @@ initialize_os_info() {
     OS_NAME="${os_id}${version_id}"
     OS_NAME_NO_DOT="${os_id}$(echo "$version_id" | tr -d '.')"
 
-    local arch=$(uname -m)
+    local arch
+    arch=$(uname -m)
     if [[ "$arch" == "aarch64" ]]; then
         OS_ARCH_SUFFIX="-aarch64"
         log "Detected aarch64 architecture, using suffix: $OS_ARCH_SUFFIX"