Remove any suggestion to --force install

This is probably a bad idea in the long run as versions can
get out of sync and other genuine warnings might be ignored.

lib/sharp.js

@@ -46,22 +46,22 @@ if (sharp) {
   // Common error messages
   if (prebuiltPlatforms.includes(runtimePlatform)) {
     const [os, cpu] = runtimePlatform.split('-');
+    const libc = os.endsWith('musl') ? ' --libc=musl' : '';
     help.push(
       '- Ensure optional dependencies can be installed:',
       '    npm install --include=optional sharp',
       '    yarn add sharp --ignore-engines',
       '- Ensure your package manager supports multi-platform installation:',
       '    See https://sharp.pixelplumbing.com/install#cross-platform',
       '- Add platform-specific dependencies:',
-      `    npm install --os=${os} --cpu=${cpu} sharp`,
-      `    npm install --force @img/sharp-${runtimePlatform}`
+      `    npm install --os=${os.replace('musl', '')}${libc} --cpu=${cpu} sharp`
     );
   } else {
     help.push(
       `- Manually install libvips >= ${minimumLibvipsVersion}`,
       '- Add experimental WebAssembly-based dependencies:',
       '    npm install --cpu=wasm32 sharp',
-      '    npm install --force @img/sharp-wasm32'
+      '    npm install @img/sharp-wasm32'
     );
   }
   if (isLinux && /(symbol not found|CXXABI_)/i.test(messages)) {