Cygwin: add docbook-xml45 package for xmlto validation.

.github/workflows/cygwin.yml

@@ -10,7 +10,7 @@ jobs:
     - uses: actions/checkout@v6.0.2
     - uses: cygwin/cygwin-install-action@v6.1
       with:
-        packages: gcc-core make binutils libssl-devel xmlto asciidoc
+        packages: gcc-core make binutils libssl-devel xmlto asciidoc docbook-xml45
     - name: Build
       shell: bash {0}
       run: make && make docs

INSTALL.md

@@ -98,7 +98,7 @@ Install Cygwin from [cygwin web site](https://cygwin.com).
 
 Following packages are required :
 ```
-$ setup-x86_64.exe -n -q -P gcc-core,make,binutils,libssl-devel,xmlto,asciidoc
+$ setup-x86_64.exe -n -q -P gcc-core,make,binutils,libssl-devel,xmlto,asciidoc,docbook-xml45
 ```
 
 To build :

docs/Makefile

@@ -21,7 +21,7 @@ clean:
 	asciidoc -d manpage -arevnumber=$(version) -arevdate=$(version_date) $<
 
 %.1: %.1.xml
-	xmlto --skip-validation man $<
+	xmlto man $<
 
 %.html: %.adoc
 	asciidoc $<