Use corepack for pnpm management

Dockerfile

@@ -2,10 +2,10 @@ FROM cloudron/base:5.0.0
 
 MAINTAINER Cloudron Support <support@cloudron.io>
 
-# Install Node.js 20 and pnpm
+# Install Node.js 20 and enable corepack for pnpm
 RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
     apt-get install -y nodejs && \
-    npm install -g pnpm@9.12.4
+    corepack enable
 
 # Set up application directory
 WORKDIR /app/code
@@ -13,9 +13,7 @@ WORKDIR /app/code
 # Clone and build Docmost
 RUN git clone https://github.com/docmost/docmost.git . && \
     rm -rf .git && \
-    corepack enable && \
-    corepack prepare pnpm@latest --activate && \
-    pnpm install --frozen-lockfile && \
+    pnpm install && \
     pnpm build
 
 # Create necessary directories