[niepce] make: allow running the widget-test target

[Hubert Figuière <hub src gnome org>]

commit 1766699c1bdfc771081933d7db785d2f31aab12a
Author: Hubert Figuière <hub figuiere net>
Date:   Sat Oct 15 22:37:04 2022 -0400

    make: allow running the widget-test target

 src/Makefile.am | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index d0eb0c6b..e267ef32 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -116,3 +116,7 @@ check-local:
 clippy:
        cd $(top_srcdir) && \
        CARGO_TARGET_DIR=$(CARGO_TARGET_DIR) cargo clippy $(CARGO_VERBOSE) $(CARGO_RELEASE_ARGS)
+
+widget-test:
+       cd $(top_srcdir) && \
+       CARGO_TARGET_DIR=$(CARGO_TARGET_DIR) cargo run --example=widget-test $(CARGO_VERBOSE) 
$(CARGO_RELEASE_ARGS)