Update .gitattributes

As per the script mentioned in Slack:

https://laminas.slack.com/archives/C4QBQUEG5/p1659021962269249?thread_ts=1659008498.914889&cid=C4QBQUEG5
https://gist.github.com/TimWolla/d2c29fa7dbd2c6de3a80cf21508cde26

Signed-off-by: Tim Düsterhus <duesterhus@woltlab.com>

Author: TimWolla

.gitattributes

@@ -1,10 +1,12 @@
 /.gitattributes export-ignore
 /.github/ export-ignore
 /.gitignore export-ignore
+/composer.lock export-ignore
 /docs/ export-ignore
 /mkdocs.yml export-ignore
 /phpcs.xml export-ignore
-/psalm.xml export-ignore
-/psalm-baseline.xml export-ignore
 /phpunit.xml.dist export-ignore
+/psalm-baseline.xml export-ignore
+/psalm.xml export-ignore
+/renovate.json export-ignore
 /test/ export-ignore