home-manager: Prevent pipe failure when reading news

On my system (Fedora 43 with Nix 2.31.3) `home-manager news` exits
from `SIGPIPE` and never writes `~/.local/share/home-manager/news-read-ids`,
resulting in news items to never be marked read.  This is caused by
piping `(import ./news.nix).news.all` through `jq` and `less` failing
with an error as soon as `less` exits, which triggers `set -o pipefail`
to exit the shell running `home-manager` itself.

Avoiding the pipe into `$PAGER` avoids the problem.

Closes: https://github.com/nix-community/home-manager/issues/8690
References: https://github.com/jqlang/jq/issues/1017
References: https://www.greenend.org.uk/rjk/tech/shellmistakes.html#pipeerrors

home-manager/home-manager

@@ -998,9 +998,11 @@ function doShowNews() {
             return 1
     esac
 
+    local formattedNewsFile="$WORK_DIR/news.txt"
     nix-instantiate --quiet --eval --json --expr "(import ${newsNixFile}).news.$newsAttr" \
         | jq -r . \
-        | ${PAGER:-less}
+        > "$formattedNewsFile"
+    ${PAGER:-less} "$formattedNewsFile"
 
     local allIds
     allIds="$(nix-instantiate --quiet --eval --expr "(import ${newsNixFile}).meta.ids")"