Correct artifact paths

[full ci]

Author: Steve Kirkland

.buildkite/unity.2020.full.yml

@@ -44,7 +44,7 @@ steps:
               - upm-package.zip
             upload:
               - features/fixtures/mazerunner/build/Windows-2020.zip
-              - features/fixtures/build_windows.log
+              - build_windows.log
         commands:
           - features/scripts/import_package.sh --windows
           - features/scripts/build_windows.sh release

.buildkite/unity.2021.yml

@@ -42,7 +42,7 @@ steps:
               - upm-package.zip
             upload:
               - features/fixtures/mazerunner/build/Windows-2021.zip
-              - features/fixtures/build_windows.log
+              - build_windows.log
         commands:
           - features/scripts/import_package.sh --windows
           - features/scripts/build_windows.sh release

.buildkite/unity.6000.full.yml

@@ -42,7 +42,7 @@ steps:
               - upm-package.zip
             upload:
               - features/fixtures/mazerunner/build/Windows-6000.zip
-              - features/fixtures/build_windows.log
+              - build_windows.log
         commands:
           - features/scripts/import_package.sh --windows
           - features/scripts/build_windows.sh release