pagserver: use vectored read path in benchmarks (#7498)

## Problem
Benchmarks don't use the vectored read path.

## Summary of changes
* Update the benchmarks to use the vectored read path for both singular
and vectored gets.
* Disable validation for the benchmarks

test_runner/fixtures/neon_fixtures.py

@@ -512,6 +512,11 @@ class NeonEnvBuilder:
             self.pageserver_get_impl = "vectored"
             log.debug('Overriding pageserver get_impl config to "vectored"')
 
+        self.pageserver_validate_vectored_get: Optional[bool] = None
+        if (validate := os.getenv("PAGESERVER_VALIDATE_VEC_GET")) is not None:
+            self.pageserver_validate_vectored_get = bool(validate)
+            log.debug(f'Overriding pageserver validate_vectored_get config to "{validate}"')
+
         assert test_name.startswith(
             "test_"
         ), "Unexpectedly instantiated from outside a test function"
@@ -1085,6 +1090,8 @@ class NeonEnv:
                 ps_cfg["get_vectored_impl"] = config.pageserver_get_vectored_impl
             if config.pageserver_get_impl is not None:
                 ps_cfg["get_impl"] = config.pageserver_get_impl
+            if config.pageserver_validate_vectored_get is not None:
+                ps_cfg["validate_vectored_get"] = config.pageserver_validate_vectored_get
 
             # Create a corresponding NeonPageserver object
             self.pageservers.append(

test_runner/regress/test_compatibility.py

@@ -228,8 +228,9 @@ def test_forward_compatibility(
     try:
         # Previous version neon_local and pageserver are not aware
         # of the new config.
-        # TODO: remove this once the code reaches main
+        # TODO: remove these once the previous version of neon local supports them
         neon_env_builder.pageserver_get_impl = None
+        neon_env_builder.pageserver_validate_vectored_get = None
 
         neon_env_builder.num_safekeepers = 3
         neon_local_binpath = neon_env_builder.neon_binpath