tests: drop runtime fetch plumbing and simplify test wrapper

Author: jgonet

popcorn/elixir/lib/popcorn/config.ex

@@ -3,12 +3,7 @@ defmodule Popcorn.Config do
   @defaults %{
     extra_apps: [],
     out_dir: nil,
-    add_tracing: false,
-    runtime: [
-      {:url, "https://github.com/software-mansion-labs/FissionVM/releases/latest/download/",
-       target: :wasm},
-      {:path, "popcorn_runtime_source/artifacts/$target"}
-    ]
+    add_tracing: false
   }
 
   def get(key) do

popcorn/elixir/lib/popcorn/utils/downloader.ex

@@ -43,3 +43,27 @@ load_env() {
         set +a
     fi
 }
+
+install_elixir_deps() {
+    local elixir_dir="$1"
+    local label="${2:-Elixir deps}"
+
+    log "Installing ${label}..."
+    (cd "${elixir_dir}" && mix deps.get)
+}
+
+install_pnpm_deps() {
+    local dir="$1"
+    local label="${2:-pnpm deps}"
+
+    log "Installing ${label}..."
+    (cd "${dir}" && pnpm install)
+}
+
+install_pnpm_workspace_deps() {
+    local repo_root="$1"
+    local label="${2:-pnpm workspace deps}"
+
+    log "Installing ${label}..."
+    (cd "${repo_root}" && pnpm install --frozen-lockfile)
+}