ci: add which dependency in dnf packages

which is used in Makefiles to check for dependencies:

Example:
export USE_ASCIIDOCTOR ?= $(shell which asciidoctor 2>/dev/null)

Signed-off-by: Radostin Stoyanov <[email protected]>

Author: rst0git

contrib/dependencies/dnf-packages.sh

@@ -37,4 +37,5 @@ dnf install -y \
 	python3-setuptools \
 	python3-wheel \
 	rubygem-asciidoctor \
+	which \
 	xmlto