ci(fresh-install): add findutils to arch/tumbleweed distro legs

.github/workflows/ci-fresh-install.yml

@@ -136,16 +136,22 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        # findutils (find) is mandatory on every leg: quick_install.sh
+        # locates the extracted xlings dir with `find`, so a missing find
+        # fails the install with exit 127 *before* mcpp ever runs. Minimal
+        # images (opensuse/tumbleweed) ship without it; arch's base merely
+        # bundles it by luck. List it explicitly everywhere — don't rely on
+        # the base image.
         include:
           - distro: fedora-latest
             image: fedora:latest
             setup: dnf -y install curl bash tar gzip xz git findutils binutils file glibc-langpack-en
           - distro: arch
             image: archlinux:latest
-            setup: pacman -Sy --noconfirm curl bash tar gzip xz git binutils file
+            setup: pacman -Sy --noconfirm curl bash tar gzip xz git findutils binutils file
           - distro: tumbleweed
             image: opensuse/tumbleweed:latest
-            setup: zypper -n install curl bash tar gzip xz git binutils file
+            setup: zypper -n install curl bash tar gzip xz git findutils binutils file
           - distro: debian-testing
             image: debian:testing
             setup: apt-get update && apt-get -y install curl bash tar gzip xz-utils git ca-certificates binutils findutils file
@@ -167,7 +173,13 @@ jobs:
       - name: Install xlings + mcpp
         run: |
           curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v0.4.38
-          echo "$HOME/.xlings/subos/current/bin" >> "$GITHUB_PATH"
+          # Deliberately NOT writing to $GITHUB_PATH here. On container
+          # images that declare no PATH in their config (opensuse/
+          # tumbleweed), appending a single dir to GITHUB_PATH makes the
+          # runner exec later steps' `sh` with only that dir on PATH —
+          # `sh` (in /usr/bin) vanishes and the next step dies with
+          # `exec: "sh": ... not found` / exit 127. Each step below already
+          # exports PATH itself, so the append is redundant anyway.
 
       - name: Configure mcpp
         run: |