Fix CI failure:

1. Add hell_fpm_path to run_tests.sh;
2. Rm unused `file_not_found_error` reference;
3. Update `fpm_filesystem::dirname`.

Author: zoziha

ci/run_tests.sh

@@ -118,5 +118,9 @@ pushd c_main
 "$fpm" run
 popd
 
+pushd hello_fpm_path
+"$fpm" run
+popd
+
 # Cleanup
 rm -rf ./*/build

src/fpm/manifest.f90

@@ -14,7 +14,7 @@ module fpm_manifest
     use fpm_manifest_library, only : library_config_t
     use fpm_mainfest_preprocess, only : preprocess_config_t
     use fpm_manifest_package, only : package_config_t, new_package
-    use fpm_error, only : error_t, fatal_error, file_not_found_error
+    use fpm_error, only : error_t, fatal_error
     use fpm_toml, only : toml_table, read_package_file
     use fpm_manifest_test, only : test_config_t
     use fpm_filesystem, only: join_path, exists, dirname, is_dir

src/fpm_filesystem.F90

@@ -219,7 +219,6 @@ function dirname(path) result (dir)
     character(:), allocatable :: dir
 
     dir = path(1:scan(path,'/\',back=.true.))
-    if (len_trim(dir) == 0) dir = "."
 
 end function dirname