chore(maintenance): improve Gitpod config

.gitpod.Dockerfile

@@ -0,0 +1,13 @@
+# See gitpod image here: https://hub.docker.com/layers/gitpod/workspace-base/latest
+FROM gitpod/workspace-base@sha256:d69d08a0e1fa62b6d8db9e7ffe63dc21a58f0242946d945d776a819aec652130
+
+USER gitpod
+
+# Install fnm to manage Node.js versions
+RUN curl -fsSL https://fnm.vercel.app/install | bash -s
+
+# Install AWS SAM CLI
+RUN curl -LO https://github.com/aws/aws-sam-cli/releases/latest/download/aws-sam-cli-linux-x86_64.zip \
+  && unzip -q aws-sam-cli-linux-x86_64.zip -d sam-installation \
+  && sudo ./sam-installation/install \
+  && rm -rf sam-installation aws-sam-cli-linux-*

.gitpod.yml

@@ -1,18 +1,14 @@
+image:
+    file: .gitpod.Dockerfile
 tasks:
   - init: |
       # Install Nodejs version specified in .nvmrc
-      nvm install
-      nvm use
-      # Install AWS SAM CLI
-      wget https://github.com/aws/aws-sam-cli/releases/latest/download/aws-sam-cli-linux-x86_64.zip
-      unzip aws-sam-cli-linux-x86_64.zip -d sam-installation
-      sudo ./sam-installation/install
-      rm -rf sam-installation aws-sam-cli-linux-*
+      fnm install
+      fnm use
       # Install repo dependencies
       npm run setup-local
 vscode:
   extensions:
     - dbaeumer.vscode-eslint
     - esbenp.prettier-vscode
     - firsttris.vscode-jest-runner
-    - amazonwebservices.aws-toolkit-vscode