fix: match requests pool_maxsize to num workers (#6805)

This avoids trashing connections just to immediately re-create them when
`num-worker` > 10. This should provide a pretty solid speedup on beefy
machines.

I'm not attaching any tests because this would be hard to test and if it
doesn't crash with an unknown keyword argument or something it means
it's probably going to be doing what we expect.

src/poetry/installation/executor.py

@@ -60,11 +60,6 @@ def __init__(
         self._dry_run = False
         self._enabled = True
         self._verbose = False
-        self._authenticator = Authenticator(
-            config, self._io, disable_cache=disable_cache
-        )
-        self._chef = Chef(config, self._env)
-        self._chooser = Chooser(pool, self._env, config)
 
         if parallel is None:
             parallel = config.get("installer.parallel", True)
@@ -76,6 +71,12 @@ def __init__(
         else:
             self._max_workers = 1
 
+        self._authenticator = Authenticator(
+            config, self._io, disable_cache=disable_cache, pool_size=self._max_workers
+        )
+        self._chef = Chef(config, self._env)
+        self._chooser = Chooser(pool, self._env, config)
+
         self._executor = ThreadPoolExecutor(max_workers=self._max_workers)
         self._total_operations = 0
         self._executed_operations = 0

src/poetry/utils/authenticator.py

@@ -17,7 +17,7 @@
 import requests.auth
 import requests.exceptions
 
-from cachecontrol import CacheControl
+from cachecontrol import CacheControlAdapter
 from cachecontrol.caches import FileCache
 from filelock import FileLock
 
@@ -128,6 +128,7 @@ def __init__(
         io: IO | None = None,
         cache_id: str | None = None,
         disable_cache: bool = False,
+        pool_size: int = 10,
     ) -> None:
         self._config = config or Config.create()
         self._io = io
@@ -153,14 +154,21 @@ def __init__(
         self.get_repository_config_for_url = functools.lru_cache(maxsize=None)(
             self._get_repository_config_for_url
         )
+        self._pool_size = pool_size
 
     def create_session(self) -> requests.Session:
         session = requests.Session()
 
         if self._cache_control is None:
             return session
 
-        session = CacheControl(sess=session, cache=self._cache_control)
+        adapter = CacheControlAdapter(
+            cache=self._cache_control,
+            pool_maxsize=self._pool_size,
+        )
+        session.mount("http://", adapter)
+        session.mount("https://", adapter)
+
         return session
 
     def get_session(self, url: str | None = None) -> requests.Session: