[FEATURE] Support GitLab CI/CD components

See renovatebot/renovate#23431

README.md

@@ -29,6 +29,9 @@ The `default.json`:
   "commitMessageTopic": "{{depName}}",
   "commitMessageExtra": " ({{{displayFrom}}} => {{{displayTo}}})",
   "composerIgnorePlatformReqs": null,
+  "customManagers":  [
+    // See below
+  ],
   "platformAutomerge": true,
   "rangeStrategy": "update-lockfile",
   "packageRules": [
@@ -47,6 +50,27 @@ The various parts explained:
       [TASK] Update <package> (<old-version> => <new-version>)
 
 - [`composerIgnorePlatformReqs`](https://docs.renovatebot.com/configuration-options/#composerignoreplatformreqs) lets Composer respect platform requirements (e.g. PHP version)
+- [`customManagers`](https://docs.renovatebot.com/modules/manager/regex/):
+
+```json
+    {
+      "customType": "regex",
+      "fileMatch": [
+        "\\.gitlab-ci\\.ya?ml$",
+        "templates/.+\\.ya?ml$"
+      ],
+      "versioningTemplate": "semver",
+      "datasourceTemplate": "gitlab-releases",
+      "registryUrlTemplate": "https://{{{registryUrl}}}",
+      "depTypeTemplate": "repository",
+      "matchStrings": [
+          "component: (?<registryUrl>[^\\s\\/]+)\\/(?<depName>\\S+)\\/[^\\s\\/]+@(?<currentValue>\\S+)"
+      ]
+    }
+```
+
+See [Support GitLab CI/CD components](https://github.com/renovatebot/renovate/issues/23431#issuecomment-1846446671)
+
 - [`platformAutomerge`](https://docs.renovatebot.com/configuration-options/#platformautomerge) enables the platform-native auto-merge capabilities so that update PRs can be merged automatically without interaction.
 - [`rangeStrategy`](https://docs.renovatebot.com/configuration-options/#rangestrategy) prefers lockfile updates (e.g. `composer.lock`), otherwise updates version constraints (e.g. `^1.0` to `^2.0`)
 - [`packageRules`](https://docs.renovatebot.com/configuration-options/#packagerules):

default.json

@@ -9,6 +9,22 @@
   "commitMessageTopic": "{{depName}}",
   "commitMessageExtra": " ({{{displayFrom}}} => {{{displayTo}}})",
   "composerIgnorePlatformReqs": null,
+  "customManagers": [
+    {
+      "customType": "regex",
+      "fileMatch": [
+        "\\.gitlab-ci\\.ya?ml$",
+        "templates/.+\\.ya?ml$"
+      ],
+      "versioningTemplate": "semver",
+      "datasourceTemplate": "gitlab-releases",
+      "registryUrlTemplate": "https://{{{registryUrl}}}",
+      "depTypeTemplate": "repository",
+      "matchStrings": [
+          "component: (?<registryUrl>[^\\s\\/]+)\\/(?<depName>\\S+)\\/[^\\s\\/]+@(?<currentValue>\\S+)"
+      ]
+    }
+  ],
   "platformAutomerge": true,
   "rangeStrategy": "update-lockfile",
   "packageRules": [