refactor: modernise RPM builder with Python tooling v2

- Migrate from legacy shell-based build system to modern Python tooling
- Update all metadata.yaml files to new schema with per-distro builds
- Standardise build scripts with curl -L, envsubst, and error handling
- Convert nfpm.yaml templates to use environment variable substitution
- Update Dockerfile to accept all package metadata as build arguments
- Modernise Makefile to use new Python build tool commands
- Update CI workflow to use tools/build instead of make

rpms/incus/metadata.yaml

@@ -1,9 +1,13 @@
-name: incus
-release: 1
-version: 6.10.1
-build:
-- distro: el/8
-  image: git.unkin.net/unkin/almalinux8-rpmbuilder:latest
-- distro: el/9
-  image: git.unkin.net/unkin/almalinux9-rpmbuilder:latest
+---
+builds:
+  - image: git.unkin.net/unkin/almalinux8-rpmbuilder:latest
+    release: '1'
+    repository: [almalinux/el8]
+    version: 6.10.1
+  - image: git.unkin.net/unkin/almalinux9-rpmbuilder:latest
+    release: '1'
+    repository: [almalinux/el9]
+    version: 6.10.1
+description: incus package
 github: lxc/incus
+name: incus

rpms/incus/resources/build.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/bash
 
+set -e
+
 # Install build dependencies
 dnf install -y \
       unzip \
@@ -24,14 +26,14 @@ dnf install -y \
       bash-completion \
       gettext \
       help2man \
-      curl
+      curl-minimal
 
 # Download and extract incus source
-curl -o /app/incus.tar.gz https://github.com/lxc/incus/archive/refs/tags/v${PACKAGE_VERSION}.tar.gz
+curl -L -o /app/incus.tar.gz https://github.com/lxc/incus/archive/refs/tags/v${PACKAGE_VERSION}.tar.gz
 tar -C /app -xf incus.tar.gz
 
 # Install specific Go version
-curl -O https://go.dev/dl/go1.24.1.linux-amd64.tar.gz
+curl -L -O https://go.dev/dl/go1.24.1.linux-amd64.tar.gz
 rm -rf /usr/local/go
 tar -C /usr/local -xzf go1.24.1.linux-amd64.tar.gz
 

rpms/incus/resources/nfpm_incus.yaml

@@ -92,7 +92,7 @@ contents:
 
 # Scripts to run during installation/removal (optional)
 scripts:
-  postinstall: ./scripts/postinstall.sh
-  preremove: ./scripts/preremove.sh
-  postremove: ./scripts/postremove.sh
-  preinstall: ./scripts/preinstall.sh
+  postinstall: ./resources/scripts/postinstall.sh
+  preremove: ./resources/scripts/preremove.sh
+  postremove: ./resources/scripts/postremove.sh
+  preinstall: ./resources/scripts/preinstall.sh