Download Vulkan SDK disk image to a temporary folder in the script

This prevents a `vulkan-sdk.dmg` file from lingering in the current
working directory after installing the Vulkan SDK.

misc/scripts/install_vulkan_sdk_macos.sh

@@ -4,10 +4,11 @@ set -euo pipefail
 IFS=$'\n\t'
 
 # Download and install the Vulkan SDK.
-curl -LO "https://sdk.lunarg.com/sdk/download/latest/mac/vulkan-sdk.dmg"
-hdiutil attach vulkan-sdk.dmg -mountpoint /Volumes/vulkan-sdk
+curl -L "https://sdk.lunarg.com/sdk/download/latest/mac/vulkan-sdk.dmg" -o /tmp/vulkan-sdk.dmg
+hdiutil attach /tmp/vulkan-sdk.dmg -mountpoint /Volumes/vulkan-sdk
 /Volumes/vulkan-sdk/InstallVulkan.app/Contents/MacOS/InstallVulkan \
     --accept-licenses --default-answer --confirm-command install
 hdiutil detach /Volumes/vulkan-sdk
+rm -f /tmp/vulkan-sdk.dmg
 
 echo 'Vulkan SDK installed successfully! You can now build Godot by running "scons".'