While setting up tests for the Node.js 25 release, I encountered the following error when node is executed: (#366)

```
libatomic.so.1: cannot open shared object file
```

This release contains an upgrade of V8 to 14.1 and, in the comment [here](https://github.com/nodejs/node/blob/main/tools/v8_gypfiles/v8.gyp#L1342-L1349) in the Node.js v8 tools code mentions:

```
# Platforms that don't have Compare-And-Swap (CAS) support need to link atomic library
# to implement atomic memory access.
```

I manually validated that adding `libatomic1` to the base-images package list restores functionality for the `node` binary.

Author: colincasey

heroku-22/setup.sh

@@ -55,6 +55,7 @@ packages=(
   libaom3
   libargon2-1
   libass9
+  libatomic1 # Used by Node.js >= 25
   libc-ares2 # Used by PgBouncer in heroku-buildpack-pgbouncer.
   libc-client2007e
   libc6-dev

heroku-24/installed-packages-amd64.txt

@@ -65,6 +65,7 @@ libarchive13t64
 libargon2-1
 libass9
 libassuan0
+libatomic1
 libattr1
 libaudit-common
 libaudit1

heroku-24/installed-packages-arm64.txt

@@ -65,6 +65,7 @@ libarchive13t64
 libargon2-1
 libass9
 libassuan0
+libatomic1
 libattr1
 libaudit-common
 libaudit1

heroku-24/setup.sh

@@ -58,6 +58,7 @@ packages=(
   less
   libargon2-1 # Used by the PHP runtime.
   libass9 # Used by FFmpeg in heroku-buildpack-activestorage-preview.
+  libatomic1 # Used by Node.js >= 25
   libc-client2007e # Used by the PHP IMAP extension.
   libcares2 # Used by PgBouncer in heroku-buildpack-pgbouncer.
   libdav1d7 # Used by FFmpeg in heroku-buildpack-activestorage-preview.