fix(ci): quote parameterized image: values in build-all-versions workflows

Strict YAML parsers reject the colon separating ${OS} and ${OS_VERSION}
in an unquoted scalar (it looks like a mapping value). Wrap the whole
image value in double quotes to make it an unambiguous string.

Mirrors the convention already used by
build-r-minor-sensitive-packages.yaml.

.crow/build-all-versions-amd64.yaml

@@ -39,7 +39,7 @@ depends_on:
 
 steps:
   - name: 'Build binaries'
-    image: reg.devxy.io/rpkgs/build-env-${OS}:${OS_VERSION}
+    image: "reg.devxy.io/rpkgs/build-env-${OS}:${OS_VERSION}"
     pull: true
     environment:
       RED_HAT_DEV_PW: