Fix depsolving perf-issues by doing repoclosure once.

backports #9387.
[nocoverage]

fixes #9388

(cherry picked from commit 4594deb)

CHANGES/9388.bugfix

@@ -0,0 +1,2 @@
+Vastly improved copy-with-depsolving performance.
+(backported from #9387)

pulp_rpm/app/depsolving.py

@@ -803,11 +803,11 @@ def run_solver_jobs(jobs):
 
         solvables_to_copy = set(solvables)
         result_solvables = set()
+        install_jobs = []
 
         while solvables_to_copy:
             # Take one solvable
             solvable = solvables_to_copy.pop()
-            install_jobs = []
 
             if solvable.name.startswith("module:"):
                 # If the solvable being installed is a module, try to install it and all of its
@@ -830,9 +830,9 @@ def run_solver_jobs(jobs):
                 unit_install_job = self._pool.Job(flags, solvable.id)
                 install_jobs.append(unit_install_job)
 
-            # Depsolve using the list of unit install jobs, add them to the results
-            solvables_copied = run_solver_jobs(install_jobs)
-            result_solvables.update(solvables_copied)
+        # Depsolve using the list of unit install jobs, add them to the results
+        solvables_copied = run_solver_jobs(install_jobs)
+        result_solvables.update(solvables_copied)
 
         solved_units = self.mapping.get_units_from_solvables(result_solvables)
         for k in unit_repo_map.keys():