Add bin to Composer Metadata (#32099) (#32106)

Backport #32099 by @maantje

This PR addresses the missing `bin` field in Composer metadata, which
currently causes vendor-provided binaries to not be symlinked to
`vendor/bin` during installation.

In the current implementation, running `composer install` does not
publish the binaries, leading to issues where expected binaries are not
available.

By properly declaring the `bin` field, this PR ensures that binaries are
correctly symlinked upon installation, as described in the [Composer
documentation](https://getcomposer.org/doc/articles/vendor-binaries.md).

Co-authored-by: Jamie Schouten <j4mie@hey.com>

modules/packages/composer/metadata.go

@@ -43,6 +43,7 @@ type Metadata struct {
 	Homepage    string            `json:"homepage,omitempty"`
 	License     Licenses          `json:"license,omitempty"`
 	Authors     []Author          `json:"authors,omitempty"`
+	Bin         []string          `json:"bin,omitempty"`
 	Autoload    map[string]any    `json:"autoload,omitempty"`
 	AutoloadDev map[string]any    `json:"autoload-dev,omitempty"`
 	Extra       map[string]any    `json:"extra,omitempty"`