mark scripts as executable
diff --git a/ext/dav1d.cmd b/ext/dav1d.cmd
old mode 100644
new mode 100755
diff --git a/ext/libjpeg.cmd b/ext/libjpeg.cmd
old mode 100644
new mode 100755
diff --git a/ext/libyuv.cmd b/ext/libyuv.cmd
old mode 100644
new mode 100755
diff --git a/ext/rav1e.cmd b/ext/rav1e.cmd
old mode 100644
new mode 100755
diff --git a/ext/svt.cmd b/ext/svt.cmd
old mode 100644
new mode 100755
diff --git a/ext/zlibpng.cmd b/ext/zlibpng.cmd
old mode 100644
new mode 100755