Ignore unsed import in dap/__init__.py

flake8 warns about dap/__init__.py because it has a number of unused
imports.  Most of these are intentional: the import is done to ensure
that the a DAP request is registered with the server object.

This patch applies a "noqa" comment to these imports, and also removes
one import that is truly unnecessary.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

gdb/python/lib/gdb/dap/__init__.py

@@ -14,25 +14,27 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import gdb
 
 # This must come before other DAP imports.
 from . import startup
 
-# Load modules that define commands.
+# Load modules that define commands.  These imports intentionally
-from . import breakpoint
+# ignore the unused import warning, as these modules are being loaded
-from . import bt
+# for their side effects -- namely, registering DAP commands with the
-from . import disassemble
+# server object.  "F401" is the flake8 "imported but unused" code.
-from . import evaluate
+from . import breakpoint  # noqa: F401
-from . import launch
+from . import bt  # noqa: F401
-from . import locations
+from . import disassemble  # noqa: F401
-from . import memory
+from . import evaluate  # noqa: F401
-from . import modules
+from . import launch  # noqa: F401
-from . import next
+from . import locations  # noqa: F401
-from . import pause
+from . import memory  # noqa: F401
-from . import scopes
+from . import modules  # noqa: F401
-from . import sources
+from . import next  # noqa: F401
-from . import threads
+from . import pause  # noqa: F401
+from . import scopes  # noqa: F401
+from . import sources  # noqa: F401
+from . import threads  # noqa: F401
 
 from .server import Server