Tweak check_float_tests.yml to run on pull_request as well as push

Author: lurch

.github/workflows/check_float_tests.yml

@@ -9,6 +9,14 @@ on:
       - src/rp2_common/pico_double/include/pico/double.h
       - test/pico_float_test/custom_float_funcs_test.c
       - test/pico_float_test/custom_double_funcs_test.c
+  pull_request:
+    paths:
+      - .github/workflows/check_float_tests.yml
+      - tools/check_float_test_names.py
+      - src/rp2_common/pico_float/include/pico/float.h
+      - src/rp2_common/pico_double/include/pico/double.h
+      - test/pico_float_test/custom_float_funcs_test.c
+      - test/pico_float_test/custom_double_funcs_test.c
 
 jobs:
   check-float-tests: