Update deploy.yml to remove problematic minifier step

The minifier that Franklin leans on is buggy and, in any case, github pages optimises stuff for us so it's not needed.

In the context of #2006, it will help to disable it to see the generated HTML more clearly.

.github/workflows/deploy.yml

@@ -58,7 +58,7 @@ jobs:
               using NodeJS; run(`$(npm_cmd()) install highlight.js`);
               using Franklin;
               Franklin.HIGHLIGHTJS[] = abspath(joinpath("_libs", "highlight", "highlight.min.js"));
-              Franklin.optimize(prerender=true);
+              Franklin.optimize(prerender=true, minify=false);
               cp(joinpath("__site", "feed.xml"), joinpath("__site", "index.xml"))' > build.log
           cat build.log