Use POSIT_CONNECT_PROJECTS secrets for helm dispatch

Align with the org-level secret pair provisioned by rstudio/github-iac
for the posit-connect-projects App. Replaces the generic APP_ID /
APP_PRIVATE_KEY names that predate the app-specific migration.

Author: bschwedler

.github/workflows/production.yml

@@ -91,8 +91,8 @@ jobs:
         id: app-token
         uses: actions/create-github-app-token@v3
         with:
-          app-id: ${{ secrets.APP_ID }}
-          private-key: ${{ secrets.APP_PRIVATE_KEY }}
+          app-id: ${{ secrets.POSIT_CONNECT_PROJECTS_APP_ID }}
+          private-key: ${{ secrets.POSIT_CONNECT_PROJECTS_PEM }}
           owner: rstudio
           repositories: helm