Add comment on where the SDL Linux dependency list comes from

Author: Exanite

sources/SDL/Native/build-linux-arm.sh

@@ -6,6 +6,7 @@ fi
 if [[ ! -z ${GITHUB_ACTIONS+x} ]]; then
     ../../../eng/native/buildsystem/download-zig.py
     export PATH="$PATH:$(readlink -f "../../../eng/native/buildsystem/zig")"
+    # Dependency list is from https://github.com/libsdl-org/SDL/blob/main/docs/README-linux.md#build-dependencies
     sudo apt-get update
     sudo apt-get install build-essential git make \
         pkg-config cmake ninja-build gnome-desktop-testing libasound2-dev libpulse-dev \

sources/SDL/Native/build-linux-arm64.sh

@@ -6,6 +6,7 @@ fi
 if [[ ! -z ${GITHUB_ACTIONS+x} ]]; then
     ../../../eng/native/buildsystem/download-zig.py
     export PATH="$PATH:$(readlink -f "../../../eng/native/buildsystem/zig")"
+    # Dependency list is from https://github.com/libsdl-org/SDL/blob/main/docs/README-linux.md#build-dependencies
     sudo apt-get update
     sudo apt-get install build-essential git make \
         pkg-config cmake ninja-build gnome-desktop-testing libasound2-dev libpulse-dev \

sources/SDL/Native/build-linux-x64.sh

@@ -6,6 +6,7 @@ fi
 if [[ ! -z ${GITHUB_ACTIONS+x} ]]; then
     ../../../eng/native/buildsystem/download-zig.py
     export PATH="$PATH:$(readlink -f "../../../eng/native/buildsystem/zig")"
+    # Dependency list is from https://github.com/libsdl-org/SDL/blob/main/docs/README-linux.md#build-dependencies
     sudo apt-get update
     sudo apt-get install build-essential git make \
         pkg-config cmake ninja-build gnome-desktop-testing libasound2-dev libpulse-dev \