Deploy kepler version release-0.7.8 instead of latest to work on arm64

Changed kepler to version release-0.7.8 because of SIGSEGV errors on arm64 (see https://github.com/sustainable-computing-io/kepler/issues/1866#issuecomment-2508109117)

scripts/post_deploy.sh

@@ -186,6 +186,7 @@ echo "......................................Finished installing SWM.............
 
 echo ".....................Installing Kepler....................................."
 cd kepler
+sed -i 's/IMAGE_TAG          ?= latest/export IMAGE_TAG   ?= release-0.7.8/g' Makefile
 make build-manifest OPTS="PROMETHEUS_DEPLOY"
 kubectl create -f _output/generated-manifest/deployment.yaml
 cd ..