feat(manager): runtime version

lib/modules/manager/api.ts

@@ -44,6 +44,7 @@ import * as helmfile from './helmfile';
 import * as helmsman from './helmsman';
 import * as helmv3 from './helmv3';
 import * as hermit from './hermit';
+import * as herokuRuntime from './heroku-runtime';
 import * as homebrew from './homebrew';
 import * as html from './html';
 import * as jenkins from './jenkins';
@@ -140,6 +141,7 @@ api.set('helmfile', helmfile);
 api.set('helmsman', helmsman);
 api.set('helmv3', helmv3);
 api.set('hermit', hermit);
+api.set('heroku-runtime', herokuRuntime);
 api.set('homebrew', homebrew);
 api.set('html', html);
 api.set('jenkins', jenkins);

lib/modules/manager/heroku-runtime/extract.spec.ts

@@ -0,0 +1,17 @@
+import { extractPackageFile } from '.';
+
+describe('modules/manager/heroku-runtime/extract', () => {
+  describe('extractPackageFile()', () => {
+    it('returns a result', () => {
+      const res = extractPackageFile('python-3.12.4\n');
+      expect(res.deps).toEqual([
+        {
+          depName: 'python',
+          commitMessageTopic: 'Python',
+          currentValue: '3.12.4',
+          datasource: 'docker',
+        },
+      ]);
+    });
+  });
+});

lib/modules/manager/heroku-runtime/extract.ts

@@ -0,0 +1,12 @@
+import { DockerDatasource } from '../../datasource/docker';
+import type { PackageDependency, PackageFileContent } from '../types';
+
+export function extractPackageFile(content: string): PackageFileContent {
+  const dep: PackageDependency = {
+    depName: 'python',
+    commitMessageTopic: 'Python',
+    currentValue: content.replaceAll('python-', '').trim(),
+    datasource: DockerDatasource.id,
+  };
+  return { deps: [dep] };
+}

lib/modules/manager/heroku-runtime/index.ts

@@ -0,0 +1,15 @@
+import type { Category } from '../../../constants';
+import { DockerDatasource } from '../../datasource/docker';
+import * as dockerVersioning from '../../versioning/docker';
+
+export { extractPackageFile } from './extract';
+
+export const supportedDatasources = [DockerDatasource.id];
+
+export const defaultConfig = {
+  fileMatch: ['^runtime.txt$'],
+  versioning: dockerVersioning.id,
+  pinDigests: false,
+};
+
+export const categories: Category[] = ['python'];

lib/modules/manager/heroku-runtime/readme.md

@@ -0,0 +1 @@
+Simply keeps the Heroku `runtime.txt` file updated.