Fix Windows platform library prefix handling in Makefile for llama.cpp #15

Job	Run time
linux-arm64-local build + test	2m 48s
linux-musl-arm64-full build + test	3m 48s
linux-arm64-full build + test	2m 54s
linux-musl-x86_64-local build + test	6m 17s
windows-x86_64-local build + test	6m 24s
android-arm64-v8a-full build	4m 42s
linux-musl-arm64-local build + test	4m 9s
android-arm64-v8a-local build	4m 32s
linux-x86_64-local build + test	4m 19s
windows-x86_64-remote build + test	1m 12s
macos-x86_64-local build	1m 43s
macos-local build + test	1m 41s
ios-remote build	47s
macos-arm64-local build + test	3m 24s
macos-x86_64-remote build	45s
macos-arm64-remote build + test	47s
linux-musl-arm64-remote build + test	22s
macos-full build + test	2m 33s
ios-sim-local build	3m 7s
android-arm64-v8a-remote build	14s
windows-x86_64-full build + test	6m 38s
macos-remote build + test	52s
ios-sim-remote build	50s
linux-musl-x86_64-remote build + test	25s
macos-arm64-full build + test	1m 48s
android-x86_64-full build + test	4m 42s
macos-x86_64-full build	2m 24s
android-aar build	4m 59s
ios-sim-full build	2m 31s
ios-full build	1m 51s
linux-arm64-remote build + test	11s
linux-x86_64-remote build + test	15s
android-armeabi-v7a-remote build	24s
apple-xcframework build	3m 8s
android-x86_64-remote build + test	1m 41s
ios-local build	1m 43s
linux-musl-x86_64-full build + test	6m 21s
linux-x86_64-full build + test	4m 6s
android-x86_64-local build + test	4m 25s
release	0s
	1h 45m 42s

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