feat: add OpenBao plugin RPMs for consul and nomad secrets engines

- Add openbao-plugin-secret-consul v0.1.0 RPM configuration
- Add openbao-plugin-secret-nomad v0.1.4 RPM configuration
- Add openbao-plugins v1.0.0 meta package that installs both plugins
- Plugins install to /opt/openbao-plugins directory
- Include pre-install scripts to create plugin directory
- Support for EL8 and EL9 distributions

rpms/openbao-plugin-secret-consul/resources/nfpm.yaml

@@ -0,0 +1,35 @@
+# nfpm.yaml
+
+name: openbao-plugin-secret-consul
+version: ${PACKAGE_VERSION}
+release: ${PACKAGE_RELEASE}
+arch: amd64
+platform: linux
+section: default
+priority: extra
+description: "OpenBao secrets engine plugin for HashiCorp Consul"
+
+maintainer: OpenBao Community
+homepage: https://github.com/openbao/openbao-plugins
+license: MPL-2.0
+
+disable_globbing: false
+
+replaces:
+  - openbao-plugin-secret-consul
+
+provides:
+  - openbao-plugin-secret-consul
+
+# Files to include in the package
+contents:
+  - src: /app/openbao-plugin-secrets-consul
+    dst: /opt/openbao-plugins/openbao-plugin-secrets-consul
+    file_info:
+      mode: 0755
+      owner: root
+      group: root
+
+# Scripts to run during installation/removal
+scripts:
+  preinstall: /app/resources/scripts/preinstall.sh