Don't track test suite artifacts by default

This commit adds the Wasm files under `testsuite/`, to
gitignore. We want to track these files, but only in very specific
cases, e.g., `prod/testsuite-base`, which includes precompiled
binaries. In such case, the binaries are forcefully tracked in git by
a CI job.

Author: saulecabrera

.gitignore

@@ -1,3 +1,10 @@
 *.wasm
 .DS_Store
 /tests/c/testsuite/
+/tests/rust/testsuite/
+/tests/assemblyscript/testsuite/
+__pycache__
+
+*~
+\#*\#
+