test: increase protocol-test-valgrind timeout

Currently libei's valgrind test setup has 100x timeout (3000s), but the
standalone protocol-test-valgrind still has 30s timeout, which is not enough
for RISC-V hardware. On Milk-V Pioneer (SG2042) it takes ~70s to complete. In
addition, `kill_gently` sends SIGKILL before the process terminates and fails
the test.

Bump protocol-test-valgrind timeout to 300s and increase timeout between kill
signals to 3s to solve the issue.

Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/329>

test/meson.build

@@ -195,7 +195,8 @@ if enable_pytest
             args: pytest_args + ['-k', 'TestEiProtocol'],
             suite: 'python',
             workdir: meson.project_build_root(),
-            env: env
+            env: env,
+            timeout: 300
         )
     endif
 

test/test_protocol.py

@@ -337,7 +337,7 @@ class Eis:
         stdout, stderr = None, None
         for _ in kill_gently(self.process):
             try:
-                stdout, stderr = self.process.communicate(timeout=1)
+                stdout, stderr = self.process.communicate(timeout=3)
                 break
             except subprocess.TimeoutExpired:
                 pass