fix(chapel-ci): verify multilocale via runtime dir, not printchplenv

Run #4 progressed past Build (Chapel 2.8.0 + bundled LLVM support
compiled in ~12 min, libchpllaunch.a + modules + cmake module files
all generated). Failed in Activate when:

  "$CHPL_HOME/util/printchplenv" --simple | grep -E '^CHPL_COMM=gasnet$'

emitted zero output then exit 1 (presumably printchplenv --simple uses
a different output format than KEY=value, or it ran into a chplenv
caching issue).

Switch to a format-independent check: Chapel's runtime layout names
$CHPL_HOME/lib/<plat>/gnu/<arch>/loc-flat/comm-gasnet/smp/<tasks>/launch-smp/
per (comm, launcher, ...) variant. Existence of comm-gasnet/smp/.../launch-smp
proves the runtime was built with our CHPL_COMM+CHPL_LAUNCHER settings —
no chpl-flag-version dependence, no parsing format risk.

Author: hyperpolymath

.github/workflows/chapel-ci.yml

@@ -319,9 +319,11 @@ jobs:
           source util/setchplenv.bash
           # Build chpl + runtime + GASNet+smp substrate
           make -j"$(nproc)"
-          # Sanity: confirm we have a multilocale chpl. Chapel 2.8.0 dropped
-          # `chpl --about`; use the canonical printchplenv utility instead.
-          "$CHPL_HOME/util/printchplenv" --simple | grep -E '^CHPL_COMM=gasnet$'
+          # Sanity: Chapel's runtime layout names a directory per (comm, launcher,
+          # tasks, ...) variant. The presence of a `comm-gasnet` runtime lib
+          # confirms the build picked up our CHPL_COMM=gasnet without depending
+          # on `chpl --about` (gone in 2.8.0) or `printchplenv` output format.
+          ls "$CHPL_HOME/lib"/*/gnu/*/loc-flat/comm-gasnet/smp/*/launch-smp 1>/dev/null
 
       - name: Activate multilocale Chapel
         id: activate
@@ -341,7 +343,7 @@ jobs:
             echo "PATH=$CHPL_HOME/bin/$(uname -s)-$(uname -m):$PATH"
           } >> "$GITHUB_ENV"
           chpl --version
-          "$CHPL_HOME/util/printchplenv" --simple | grep -E '^CHPL_COMM=gasnet$'
+          ls "$CHPL_HOME/lib"/*/gnu/*/loc-flat/comm-gasnet/smp/*/launch-smp 1>/dev/null
 
       - name: Build mass-panic against multilocale Chapel
         working-directory: chapel