Run gpg in batch mode (#9732)

Do not prompt for any reason, especially not if a repomd.xml.asc already
exists when signing repomd.xml. Attempting to prompt (instead of
overwriting) results in publish failures like the following:

  + gpg --detach-sign --armor /rpmrepo/teleport/repodata/repomd.xml
  gpg: cannot open '/dev/tty': No such device or address

Contributes to #9726.

(cherry picked from commit 0fb71e9)

.drone.yml

@@ -3971,7 +3971,7 @@ steps:
         echo "$GPG_RPM_SIGNING_ARCHIVE" | base64 -d | tar -xzf - -C $GNUPGHOME
         chown -R root:root $GNUPGHOME
       # Sign rpm repo metadata (yum clients will automatically look for and verify repodata/repomd.xml.asc)
-      - gpg --detach-sign --armor /rpmrepo/teleport/repodata/repomd.xml
+      - gpg --batch --yes --detach-sign --armor /rpmrepo/teleport/repodata/repomd.xml
       - cat /rpmrepo/teleport/repodata/repomd.xml.asc
       - rm -rf $GNUPGHOME
 
@@ -4087,6 +4087,6 @@ volumes:
       name: drone-s3-debrepo-pvc
 ---
 kind: signature
-hmac: 8af156cf5b97dce8c9dcae7b3a189fafd910f692f86dbf11a2e500f0185144d9
+hmac: ab03c06bffc03426f49ea126d87dd41dc1c024ac5cbbd12d76298b0463c5f8c8
 
 ...