fix(chapel-ci): replace dropped 'chpl --about' with printchplenv

Run #3 cold build completed successfully (~12 min, libchpllaunch.a +
modules + cmake module files all generated), then the post-build
sanity check failed with:

  Unrecognized flag: '--about' (use '-h' for help)

Chapel 2.8.0 dropped 'chpl --about'. Use the canonical
$CHPL_HOME/util/printchplenv --simple invocation instead — it prints
KEY=value lines (so the regex anchor changes from ':\s+' to '=').

Applied in both 'Build Chapel from source' and 'Activate multilocale
Chapel' steps.

Author: hyperpolymath

.github/workflows/chapel-ci.yml

@@ -319,8 +319,9 @@ jobs:
           source util/setchplenv.bash
           # Build chpl + runtime + GASNet+smp substrate
           make -j"$(nproc)"
-          # Sanity: confirm we have a multilocale chpl
-          ./bin/*/chpl --about | grep -E 'CHPL_COMM:\s+gasnet'
+          # Sanity: confirm we have a multilocale chpl. Chapel 2.8.0 dropped
+          # `chpl --about`; use the canonical printchplenv utility instead.
+          "$CHPL_HOME/util/printchplenv" --simple | grep -E '^CHPL_COMM=gasnet$'
 
       - name: Activate multilocale Chapel
         id: activate
@@ -340,7 +341,7 @@ jobs:
             echo "PATH=$CHPL_HOME/bin/$(uname -s)-$(uname -m):$PATH"
           } >> "$GITHUB_ENV"
           chpl --version
-          chpl --about | grep CHPL_COMM
+          "$CHPL_HOME/util/printchplenv" --simple | grep -E '^CHPL_COMM=gasnet$'
 
       - name: Build mass-panic against multilocale Chapel
         working-directory: chapel