sys-apps/pnpm-bin: add net-libs/nodejs[corepack] as a blocker

randomly found this gem of a file conflict out when I was recently
installing nodejs with the corepack use flag to test out a few software
and add the packages

lo and behold, nodejs failed to install on the src_install phase because
of file collision, and i saw that pnpm-bin was the issue because it
wasn't blocking nodejs[corepack]

one could easily check this by doing

```
❯ equery f nodejs | grep -e '/usr/bin/'
/usr/bin/corepack
/usr/bin/node
/usr/bin/npm
/usr/bin/npx
/usr/bin/pnpm
/usr/bin/pnpx
/usr/bin/yarn
/usr/bin/yarnpkg
```

this commit should fix this issue

Signed-off-by: ingenarel (NeoJesus) <ingenarel_neojesus@disroot.org>
Part-of: https://codeberg.org/gentoo/guru/pulls/12

sys-apps/pnpm-bin/pnpm-bin-10.19.0.ebuild

@@ -1,4 +1,4 @@
-# Copyright 2023-2025 Gentoo Authors
+# Copyright 2023-2026 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=8
@@ -18,6 +18,8 @@ KEYWORDS="-* ~amd64 ~arm64"
 
 RESTRICT="strip"
 
+RDEPEND="!net-libs/nodejs[corepack]"
+
 QA_PREBUILT="usr/bin/pnpm"
 
 src_install() {