CI/Flatpak: Switch from JSON -> YAML

Actually lets me have comments...

scripts/flatpak/modules/26-soundtouch.yaml

@@ -0,0 +1,27 @@
+name: soundtouch
+buildsystem: cmake-ninja
+builddir: true
+config-opts:
+  - "-DCMAKE_BUILD_TYPE=Release"
+
+  # Use clang with LTO for speed.
+  - "-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON"
+  - "-DCMAKE_C_COMPILER=/usr/lib/sdk/llvm17/bin/clang"
+  - "-DCMAKE_CXX_COMPILER=/usr/lib/sdk/llvm17/bin/clang++"
+  - "-DCMAKE_EXE_LINKER_FLAGS_INIT=-fuse-ld=lld"
+  - "-DCMAKE_MODULE_LINKER_FLAGS_INIT=-fuse-ld=lld"
+  - "-DCMAKE_SHARED_LINKER_FLAGS_INIT=-fuse-ld=lld"
+build-options:
+  strip: true
+sources:
+  - type: git
+    url: "https://github.com/stenzek/soundtouch.git"
+    commit: "463ade388f3a51da078dc9ed062bf28e4ba29da7"
+cleanup:
+  - /bin
+  - /include
+  - /lib/*.a
+  - /lib/*.la
+  - /lib/cmake
+  - /lib/pkgconfig
+  - /share