Update composer/ca-bundle requirement in the composer-packages group

Updates the requirements on [composer/ca-bundle](https://github.com/composer/ca-bundle) to permit the latest version.

Updates `composer/ca-bundle` to 1.5.6
- [Release notes](https://github.com/composer/ca-bundle/releases)
- [Commits](composer/ca-bundle@1.5.5...1.5.6)

---
updated-dependencies:
- dependency-name: composer/ca-bundle
  dependency-type: direct:development
  dependency-group: composer-packages
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

composer.json

@@ -18,7 +18,7 @@
 		"ext-dom": "*"
 	},
 	"require-dev": {
-		"composer/ca-bundle": "1.5.5",
+		"composer/ca-bundle": "1.5.6",
 		"squizlabs/php_codesniffer": "3.10.3",
 		"wp-coding-standards/wpcs": "~3.1.0",
 		"phpcompatibility/phpcompatibility-wp": "~2.1.3",