Add a WSL path to the test runner

run_tests.sh only knew one way to reach a Godot: `proot-distro login ubuntu`
and the arm64 build at /root. On WSL there is no container and no arm64
binary, so the suite could not be run from a desktop at all.

The platform is detected from /proc/version, and decides two things. Which
Godot: on WSL a Linux `godot` on PATH if there is one, otherwise the newest
Windows build already sitting on /mnt/c - the *_console.exe specifically,
since the plain .exe is a GUI-subsystem binary that detaches from the
terminal and would leave every test log empty. And whether to copy the
project first: that copy exists to get off Android's FUSE bridge, and a
Windows Godot already reads C: natively, so WSL runs in place.

_run_inside.sh now takes the binary as its first argument instead of
hardcoding it, and run_tests.sh calls it directly where there is no
container to enter. The scheduling, timeouts and verdicts are unchanged and
shared by both paths.

120/120 on WSL in 48s with JOBS=6.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -13,3 +13,7 @@ android/build/
 
 # Android's "don't index this as media" marker, not project content.
 .nomedia
+
+# Per-test verdicts from the last tests/run_tests.sh, kept only so a long run
+# whose terminal output was lost can still be read back.
+.test-results/