Fetch specific OctoPrint from GitHub

If we fetch it from PyPI, it might not be available *right* after a
OctoPrint/OctoPrint side release trigger arrives. Apparently it takes
a whee bit to propagate through.

scripts/01-update-octoprint

@@ -7,7 +7,8 @@ source /common.sh
 install_cleanup_trap
 
 if [ -n "$OCTOPRINT_VERSION" ]; then
-    sudo -u pi /home/pi/oprint/bin/pip install -U OctoPrint==$OCTOPRINT_VERSION
+    # fetch from GitHub since PyPI might not yet be synced through right after a fresh release
+    sudo -u pi /home/pi/oprint/bin/pip install -U https://github.com/OctoPrint/OctoPrint/archive/refs/tags/$OCTOPRINT_VERSION.zip
 else
     sudo -u pi /home/pi/oprint/bin/pip install -U OctoPrint
 fi