Change apt package list to install libpython3-dev

Change-Id: I40794effc6d3d74123256e7364f56824d1f2273e

install-prereqs.sh

diff --git a/install-prereqs.sh b/install-prereqs.sh
index f91045c..68d5ec0 100755
--- a/install-prereqs.sh
+++ b/install-prereqs.sh
@@ -58,7 +58,7 @@
     libglib2.0-dev-bin
     libgtk2.0-0
     libpixman-1-dev
-    libpython3.9
+    libpython3-dev
     libsqlite3-dev
     libssl-dev
     libtinfo-dev