Silence new -Wmissing-home-modules warning in +monolithic configuration

`cabal-install.cabal` would greatly benefit from common stanzas (haskell#2832)
as it would help reduce the redundancy singnificantly.

Author: hvr

cabal-install/cabal-install.cabal

@@ -462,6 +462,33 @@ executable cabal
         MemoryUsageTests
         SolverQuickCheck
         IntegrationTests2
+
+        UnitTests.Distribution.Client.ArbitraryInstances
+        UnitTests.Distribution.Client.FileMonitor
+        UnitTests.Distribution.Client.GZipUtils
+        UnitTests.Distribution.Client.Glob
+        UnitTests.Distribution.Client.IndexUtils.Timestamp
+        UnitTests.Distribution.Client.InstallPlan
+        UnitTests.Distribution.Client.JobControl
+        UnitTests.Distribution.Client.ProjectConfig
+        UnitTests.Distribution.Client.Sandbox
+        UnitTests.Distribution.Client.Sandbox.Timestamp
+        UnitTests.Distribution.Client.Store
+        UnitTests.Distribution.Client.Tar
+        UnitTests.Distribution.Client.Targets
+        UnitTests.Distribution.Client.UserConfig
+        UnitTests.Distribution.Solver.Modular.Builder
+        UnitTests.Distribution.Solver.Modular.DSL
+        UnitTests.Distribution.Solver.Modular.DSL.TestCaseUtils
+        UnitTests.Distribution.Solver.Modular.MemoryUsage
+        UnitTests.Distribution.Solver.Modular.QuickCheck
+        UnitTests.Distribution.Solver.Modular.RetryLog
+        UnitTests.Distribution.Solver.Modular.Solver
+        UnitTests.Distribution.Solver.Modular.WeightedPSQ
+        UnitTests.Options
+
+        Paths_cabal_install
+
       cpp-options: -DMONOLITHIC
       build-depends:
         Cabal      >= 2.1 && < 2.2,