CI: don't include debug symbols for musl builds #3654

Job	Run time
alpine 3.19.0 (musl)	9m 27s
coverage (ubuntu-20.04)	4m 59s
Ubuntu/Debian packaging (Ubuntu 20.04)	6m 45s
ubuntu-20.04 (package, non-mavsdk_server)	6m 14s
ubuntu-22.04 (package, non-mavsdk_server)	5m 12s
linux-armv6	3m 58s
android-arm	5m 21s
linux-armv7	3m 58s
linux-armv6-musl	10m 18s
linux-armv7l-musl	10m 0s
ios	8m 46s
linux-arm64	3m 58s
linux-arm64-musl	10m 43s
ios_simulator	9m 15s
android-arm64	5m 19s
android-x86	5m 16s
macOS	18m 40s
android-x86_64	5m 10s
ubuntu-20.04 (mavsdk, hunter)	3m 57s
macOS-framework	19m 47s
ubuntu-20.04 (non-mavsdk_server, non-superbuild)	5m 19s
ubuntu-22.04 (style and proto check)	1m 51s
Windows	11m 7s
ubuntu-20.04 (mavsdk_server, superbuild)	41m 38s
ubuntu-22.04 (mavsdk_server, superbuild)	10m 31s
iOS XCFramework	1m 22s
	3h 48m 51s

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