fix(resolver): catch NoSuchProjectError in wheel server fallback

Fix e2e test failure in test_post_bootstrap_hook.sh by catching
NoSuchProjectError when trying wheel servers.

The previous fix (423d5c0) only caught ResolverException but not
NoSuchProjectError which is raised when a project doesn't exist
on a wheel server. Both are legitimate "not found" cases where
we should try the next wheel server.

Now catches both expected exceptions:
- ResolverException: no matching candidates found
- NoSuchProjectError: project doesn't exist on server

Still lets unexpected failures propagate:
- Auth failures (401)
- Network errors (ConnectionError)
- Plugin bugs (AttributeError, etc.)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Signed-off-by: Rohan Devasthale <rdevasth@redhat.com>

Author: rd4398

src/fromager/bootstrap_requirement_resolver.py

@@ -9,6 +9,7 @@
 import logging
 import typing
 
+import pypi_simple.errors
 import resolvelib.resolvers
 from packaging.requirements import Requirement
 from packaging.version import Version
@@ -183,8 +184,11 @@ def _resolve(
                         logger.debug(
                             f"{req.name}: no prebuilt wheel found on {url}, trying next server"
                         )
-                except resolvelib.resolvers.ResolverException as e:
-                    # Only catch "no match found" exceptions - try next server
+                except (
+                    resolvelib.resolvers.ResolverException,
+                    pypi_simple.errors.NoSuchProjectError,
+                ) as e:
+                    # Only catch expected "not found" exceptions - try next server
                     # Let auth failures, network errors, and plugin bugs propagate
                     logger.debug(f"{req.name}: no matching wheel on {url}: {e}")
                     continue