fix(deploy-script): favicon generator (#2466)

Without this change, the script tries to execute an `index.js` located
in a folder that does not have such a file.

deploy/scripts/favicon_generator.sh

@@ -4,7 +4,8 @@ master_url="${FAVICON_MASTER_URL:-$NEXT_PUBLIC_NETWORK_ICON}"
 export MASTER_URL="$master_url"
 
 cd ./deploy/tools/favicon-generator
-node "$(dirname "$0")/index.js"
+yarn install --frozen-lockfile
+node "$(pwd)/index.js"
 if [ $? -ne 0 ]; then
     cd ../../../
     exit 1