fix: update arv's public key in allowed_signers (#33)

Author: arv

.github/signing/allowed_signers

@@ -40,7 +40,7 @@
 #
 
 aa@roci.dev namespaces="git",valid-after="20260708" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFq/gXedDlqUPHobZzm9VTzcZTwwf78oDJJFDZ1ev3KL aa-greybook-2026
-arv@roci.dev namespaces="git",valid-after="20260701" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBSXMQ1oBIet6Xf9S/Bqdd6bRV0Z8TiyVn2JAMvmO5cj arv-new-mac-2026
+arv@roci.dev namespaces="git",valid-after="20260701" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAO4/lUPlrtrnFVR7aSaGRwu1r7dAyBbL93iUqgJA2wR arv-new-mac-2026
 cesar@roci.dev namespaces="git",valid-after="20260701" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAINdgtuMD+cq/AmdHi/Nu1VeLjee7zA36gXyDiR+i9Y/x cesar-new-mac-2026
 chase@roci.dev namespaces="git",valid-after="20260701" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBaObZrJF4AbqfGLAWgmXPfF1tXYp6cuXIjAsTAKwlpd chase-new-mac-2026
 d@roci.dev namespaces="git",valid-after="20260707" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBbNqV94EUcC3bf0j+B6AAFMjkEYkUZ7YBTvh1TAnItd darick-new-mac-2026