Add secrets for builder

.sops.yaml

@@ -2,6 +2,7 @@ keys:
   - &primary age1ee5udznhadk6m7jtglu4709rep080yjyd2ukzdl8jma4mm92y3psv0slpg
   - &aspi-ssh age1q8lc5340gz5xw2f57nglrss68wv0j0hf36py2pdtrl6ky3yrq9qqk0njr4
   - &pianonix-ssh age1hsmfz8fjxu83sax9lr487h8xr6cyge0apdq4zpge4c8jpcjj2cksj825ct
+  - &builder-ssh age1kw4kmdm45zprvdkrrpvgq966l7585vhusmum083qlwnr0xxgd3uqatcyja
 creation_rules:
   - path_regex: secrets/secrets.yaml$
     key_groups:
@@ -10,6 +11,12 @@ creation_rules:
       - *aspi-ssh
       - *pianonix-ssh
 
+  - path_regex: secrets/secrets-builder.yaml$
+    key_groups:
+    - age:
+      - *primary
+      - *builder-ssh
+
   - path_regex: secrets/.+
     key_groups:
     - age: