chore: remove unused 'ci' environment from release workflows

The ci environment gate is no longer needed (it predated the JFrog
migration and gated CodeArtifact AWS credential approval). Removing it
also clears the approval gate that left release runs stuck in 'waiting'.

Author: davidacevedo

.github/workflows/prerelease.yml

@@ -22,7 +22,6 @@ permissions:
 jobs:
   prerelease:
     runs-on: ubuntu-latest
-    environment: ci
     steps:
       - uses: actions/checkout@v5
       - uses: actions/setup-node@v6

.github/workflows/release-please.yml

@@ -10,7 +10,6 @@ permissions: write-all
 jobs:
   release-github:
     runs-on: ubuntu-latest
-    environment: ci
     outputs:
       release_created: ${{ steps.release.outputs.release_created }}
     steps: