Update Node.js Dockerfile to install Yarn differently (#1165)

The Yarn GPG key (6A010C5166006599AA17F08146C2130DFD2497F5) can no
longer be fetched from keyservers, it returns "no user ID". So the
signature verification fails. So let's just download yarn via npm and
simplify this.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Build-only change confined to the Dockerfile; main risk is potential
reproducibility/supply-chain differences from switching Yarn
installation method.
> 
> **Overview**
> Updates `templates/base/e2b.Dockerfile` to install Yarn via `npm
install -g yarn@1.22.19` instead of downloading and GPG-verifying the
Yarn tarball, removing the keyserver dependency and associated
verification steps.
> 
> Also normalizes the Node version env var syntax from `ENV NODE_VERSION
20.9.0` to `ENV NODE_VERSION=20.9.0`.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
243ce4b. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: tomassrnka

templates/base/e2b.Dockerfile

@@ -10,7 +10,7 @@ RUN DEBIAN_FRONTEND=noninteractive apt-get update && apt-get install -y \
 RUN groupadd --gid 1000 node \
   && useradd --uid 1000 --gid node --shell /bin/bash --create-home node
 
-ENV NODE_VERSION 20.9.0
+ENV NODE_VERSION=20.9.0
 
 RUN ARCH= && dpkgArch="$(dpkg --print-architecture)" \
   && case "${dpkgArch##*-}" in \
@@ -55,26 +55,5 @@ RUN ARCH= && dpkgArch="$(dpkg --print-architecture)" \
   && node --version \
   && npm --version
 
-ENV YARN_VERSION 1.22.19
-
-RUN set -ex \
-  # use pre-existing gpg directory, see https://github.com/nodejs/docker-node/pull/1895#issuecomment-1550389150
-  && export GNUPGHOME="$(mktemp -d)" \
-  && for key in \
-    6A010C5166006599AA17F08146C2130DFD2497F5 \
-  ; do \
-    gpg --batch --keyserver hkps://keys.openpgp.org --recv-keys "$key" || \
-    gpg --batch --keyserver keyserver.ubuntu.com --recv-keys "$key" ; \
-  done \
-  && curl -fsSLO --compressed "https://yarnpkg.com/downloads/$YARN_VERSION/yarn-v$YARN_VERSION.tar.gz" \
-  && curl -fsSLO --compressed "https://yarnpkg.com/downloads/$YARN_VERSION/yarn-v$YARN_VERSION.tar.gz.asc" \
-  && gpg --batch --verify yarn-v$YARN_VERSION.tar.gz.asc yarn-v$YARN_VERSION.tar.gz \
-  && gpgconf --kill all \
-  && rm -rf "$GNUPGHOME" \
-  && mkdir -p /opt \
-  && tar -xzf yarn-v$YARN_VERSION.tar.gz -C /opt/ \
-  && ln -s /opt/yarn-v$YARN_VERSION/bin/yarn /usr/local/bin/yarn \
-  && ln -s /opt/yarn-v$YARN_VERSION/bin/yarnpkg /usr/local/bin/yarnpkg \
-  && rm yarn-v$YARN_VERSION.tar.gz.asc yarn-v$YARN_VERSION.tar.gz \
-  # smoke test
+RUN npm install -g yarn@1.22.19 \
   && yarn --version