release-manifests: use native fetch

Signed-off-by: MT Lewis <mtlewis@users.noreply.github.com>

.changeset/happy-forks-listen.md

@@ -0,0 +1,5 @@
+---
+'@backstage/release-manifests': patch
+---
+
+Switch to native fetch for loading release manifests

packages/release-manifests/package.json

@@ -35,9 +35,6 @@
     "postpack": "backstage-cli package postpack",
     "test": "backstage-cli package test"
   },
-  "dependencies": {
-    "cross-fetch": "^4.0.0"
-  },
   "devDependencies": {
     "@backstage/cli": "workspace:^",
     "@backstage/test-utils": "workspace:^",

packages/release-manifests/src/manifest.ts

@@ -14,8 +14,6 @@
  * limitations under the License.
  */
 
-import fetch from 'cross-fetch';
-
 const VERSIONS_BASE_URL = 'https://versions.backstage.io';
 const GITHUB_RAW_BASE_URL =
   'https://raw.githubusercontent.com/backstage/versions/main';

yarn.lock

@@ -8295,7 +8295,6 @@ __metadata:
   dependencies:
     "@backstage/cli": "workspace:^"
     "@backstage/test-utils": "workspace:^"
-    cross-fetch: ^4.0.0
     msw: ^1.0.0
   languageName: unknown
   linkType: soft