chore: add remove-signer command, fix bugs, and update release notes

- Add registry admin remove-signer command to remove a signer and all their authorizations
- Fix remove_package_signer condition (is_some -> is_none) for correct not-found error
- Use log_err() instead of silently swallowing asset fetch errors
- Trim leading '#' from version in s9pk publish path
- Add --delete-removed to s3 sync in publish-deb.sh
- Expand v0.4.0 release notes with additional features
- Regenerate man pages and add i18n entries

core/man/start-cli/start-cli-s9pk-inspect-commitment.1

@@ -2,11 +2,11 @@
 .el .ds Aq '
 .TH start-cli-s9pk-inspect-commitment 1  "commitment " 
 .SH NAME
-start\-cli\-s9pk\-inspect\-commitment \- about.display\-s9pk\-root\-sighash\-and\-maxsize
+start\-cli\-s9pk\-inspect\-commitment \- Display the s9pk root signature hash and max size
 .SH SYNOPSIS
 \fBstart\-cli s9pk inspect commitment\fR [\fB\-\-format\fR] [\fB\-h\fR|\fB\-\-help\fR] 
 .SH DESCRIPTION
-about.display\-s9pk\-root\-sighash\-and\-maxsize
+Display the s9pk root signature hash and max size
 .SH OPTIONS
 .TP
 \fB\-\-format\fR