renovate: Work around bug in atomically package (#41261)

When #40842 updated `configstore`, that brought in `atomically` v2.0.3
which has a bug where it crashes if the current user is not listed in
`/etc/passwd`, which happens inside our docker container during the
renovate run.

Work around this by making sure an appropriate entry is added to
`/etc/passwd` inside the container.

.github/files/renovate-post-upgrade-run.sh

@@ -7,4 +7,15 @@ if [[ ! -e /tmp/dummy-log/xdebug_remote.log ]]; then
 fi
 
 docker pull --quiet ghcr.io/automattic/jetpack-wordpress-dev:latest
-docker run --rm --workdir "$PWD" --user $EUID --volume /tmp/:/tmp/ --volume /tmp/dummy-log:/var/log/php ghcr.io/automattic/jetpack-wordpress-dev:latest /tmp/monorepo/.github/files/renovate-post-upgrade.sh "$@"
+
+# Work around https://github.com/fabiospampinato/atomically/issues/13 by extracting /etc/passwd from the container and appending the entry for $EUID to it.
+TMPFILE=$( mktemp )
+function cleanup {
+	rm -f "$TMPFILE"
+}
+trap cleanup exit
+chmod 0644 "$TMPFILE"
+docker run --rm ghcr.io/automattic/jetpack-wordpress-dev:latest cat /etc/passwd > "$TMPFILE"
+getent passwd $EUID >> "$TMPFILE"
+
+docker run --rm --workdir "$PWD" --user $EUID --volume "$TMPFILE":/etc/passwd --volume /tmp/:/tmp/ --volume /tmp/dummy-log:/var/log/php ghcr.io/automattic/jetpack-wordpress-dev:latest /tmp/monorepo/.github/files/renovate-post-upgrade.sh "$@"