fix: correct build_args param name; remove MCPanel from Remotes; skip Suggests

- Fix build_args (underscore not hyphen) - was silently ignored, causing
  vignettes to be built during R CMD build and failing on Windows
- Remove MCPanel from Remotes - was causing setup failures on macOS/oldrel-1
  due to C++ compilation issues
- Add dependencies: hard to only install Imports/Depends, skip Suggests
- _R_CHECK_FORCE_SUGGESTS_=false handles missing Suggests at check time

Author: Mike Nguyen

.github/workflows/R-CMD-check.yaml

@@ -45,10 +45,11 @@ jobs:
         with:
           extra-packages: any::rcmdcheck
           needs: check
+          dependencies: '"hard"'
 
       - uses: r-lib/actions/check-r-package@v2
         with:
           upload-snapshots: true
           error-on: '"error"'
-          build-args: 'c("--no-build-vignettes")'
+          build_args: 'c("--no-build-vignettes")'
           args: 'c("--no-manual", "--no-vignettes")'

DESCRIPTION

@@ -123,6 +123,5 @@ Imports:
     plm (>= 2.6.3),
     MASS
 Remotes:
-    synth-inference/synthdid@70c1ce3eac58e28c30b67435ca377bb48baa9b8a,
-    susanathey/MCPanel
+    synth-inference/synthdid@70c1ce3eac58e28c30b67435ca377bb48baa9b8a
 VignetteBuilder: knitr