chore(main): release 2.15.4 (#2576)

Author: release-please[bot]

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## [2.15.4](https://github.com/googleapis/google-api-php-client/compare/v2.15.3...v2.15.4) (2024-03-06)
+
+
+### Bug Fixes
+
+* Updates phpseclib because of a security issue ([#2574](https://github.com/googleapis/google-api-php-client/issues/2574)) ([633d41f](https://github.com/googleapis/google-api-php-client/commit/633d41f1b65fdb71a83bf747f7a3ad9857f6d02a))
+
 ## [2.15.3](https://github.com/googleapis/google-api-php-client/compare/v2.15.2...v2.15.3) (2024-01-04)