SDL_mixer: Make sure we include Get-GitModules.ps1 in the dist archive

From 85ca98c03f1655776a5ae0aa9fb24b204291c1d4 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 29 Nov 2023 19:37:26 -0800
Subject: [PATCH] Make sure we include Get-GitModules.ps1 in the dist archive

---
 Makefile.in | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile.in b/Makefile.in
index 006a8fb9..b0a73783 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -61,6 +61,7 @@ SRC_DIST =			\
 	cmake			\
 	configure		\
 	configure.ac		\
+	external/Get-GitModules.ps1	\
 	external/download.sh	\
 	include/SDL_mixer.h	\
 	mingw			\