Retire legacy KEYGRIP secret (#4275)

Author: Gedochao

.github/workflows/ci.yml

@@ -2205,7 +2205,6 @@ jobs:
       - run: ./mill -i ci.updateCentOsPackages
         env:
           PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
-          KEYGRIP: ${{ secrets.KEYGRIP }}
           PGP_SECRET: ${{ secrets.PGP_SECRET }}
           GPG_EMAIL: ${{ secrets.GPG_EMAIL }}
 

build.mill

@@ -2016,8 +2016,6 @@ object ci extends Module {
       "PGP_PASSPHRASE",
       "--env",
       "GPG_EMAIL",
-      "--env",
-      "KEYGRIP",
       "--privileged",
       "fedora:40",
       "sh",