[WIP] Fix disposal of RangeRetriever in ADStoreCtx

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>new RangeRetriever(groupDE, "member", false) is not disposed at the end of the function</issue_title>
<issue_description>### Description

dotnet 6.0

File: /src/libraries/System.DirectoryServices.AccountManagement/src/System/DirectoryServices/AccountManagement/AD/ADStoreCtx.cs:1795
Problem: new RangeRetriever(groupDE, "member", false) is not disposed at the end of the function

Reproduction Steps

1. Role: detected
   detected
   [ADStoreCtx.cs:[1795:0]](

2. Role: tracepoint
   2.1 Step 1: Condition g.fakePrincipal taking any branch
   [ADStoreCtx.cs:[1750:17]]
   2.2 Step 2: Condition p.ContextType != ContextType.Domain taking any branch
   [ADStoreCtx.cs:[1757:17]]
   2.3 Step 3: Condition g.UnderlyingObject != null taking any branch
   [ADStoreCtx.cs:[1763:26]]
   2.4 Step 4: Condition p.fakePrincipal taking any branch
   [ADStoreCtx.cs:[1768:18]]
   2.5 Step 5: Condition Sid == null taking false branch
   [ADStoreCtx.cs:[1817:17]]
   2.6 Step 6: Condition string.IsNullOrEmpty(this.UserSuppliedServerName) taking any branch
   [ADStoreCtx.cs:[1827:42]]
   2.7 Step 7: Condition stringSid == null taking false branch
   [ADStoreCtx.cs:[1838:21]]
   2.8 Step 8: Condition sr == null taking any branch
   [ADStoreCtx.cs:[1855:21]]
   no escape
   [ADStoreCtx.cs:[1861:45]]
   2.9 Step 9: Exiting the foreach
   [ADStoreCtx.cs:[1861:45]]
   2.10 Step 10: Condition cachedMembersEnum is null taking any branch
   [ADStoreCtx.cs:[1861:45]]
   2.11 Step 11: Condition ds != null taking any branch
   [ADStoreCtx.cs:[1876:21]]
   2.12 Step 12: Condition defaultNCDirEntry != null taking any branch
   [ADStoreCtx.cs:[1880:21]]

Expected behavior

memory leak

Actual behavior

same

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

Found by Linux Verification Center (linuxtesting.org) with SVACE.</issue_description>

Comments on the Issue (you are @copilot in this section)

@ Tagging subscribers to this area: @dotnet/area-system-directoryservices, @jay98014 See info in [area-owners.md](https://github.com/dotnet/runtime/blob/main/docs/area-owners.md) if you want to be subscribed.

Issue Details

---

Description

dotnet 6.0

File: /src/libraries/System.DirectoryServices.AccountManagement/src/System/DirectoryServices/AccountManagement/AD/ADStoreCtx.cs:1795
Problem: new RangeRetriever(groupDE, "member", false) is not disposed at the end of the function

Reproduction Steps

1. Role: detected
   detected
   [ADStoreCtx.cs:[1795:0]](

2. Role: tracepoint
   2.1 Step 1: Condition g.fakePrincipal taking any branch
   [ADStoreCtx.cs:[1750:17]]
   2.2 Step 2: Condition p.ContextType != ContextType.Domain taking any branch
   [ADStoreCtx.cs:[1757:17]]
   2.3 Step 3: Condition g.UnderlyingObject != null taking any branch
   [ADStoreCtx.cs:[1763:26]]
   2.4 Step 4: Condition p.fakePrincipal taking any branch
   [ADStoreCtx.cs:[1768:18]]
   2.5 Step 5: Condition Sid == null taking false branch
   [ADStoreCtx.cs:[1817:17]]
   2.6 Step 6: Condition string.IsNullOrEmpty(this.UserSuppliedServerName) taking any branch
   [ADStoreCtx.cs:[1827:42]]
   2.7 Step 7: Condition stringSid == null taking false branch
   [ADStoreCtx.cs:[1838:21]]
   2.8 Step 8: Condition sr == null taking any branch
   [ADStoreCtx.cs:[1855:21]]
   no escape
   [ADStoreCtx.cs:[1861:45]]
   2.9 Step 9: Exiting the foreach
   [ADStoreCtx.cs:[1861:45]]
   2.10 Step 10: Condition cachedMembersEnum is null taking any branch
   [ADStoreCtx.cs:[1861:45]]
   2.11 Step 11: Condition ds != null taking any branch
   [ADStoreCtx.cs:[1876:21]]
   2.12 Step 12: Condition defaultNCDirEntry != null taking any branch
   [ADStoreCtx.cs:[1880:21]]

Expected behavior

memory leak

Actual behavior

same

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Author:	achufistov
Assignees:	-
Labels:	area-System.DirectoryServices, untriaged
Milestone:	-

@danmoseley The code owners would likely welcome a PR or PRs for these. The library is considered mature so there is a risk calculus. There is the question of testing but such changes are often hard to write a test for.

Fixes #94755

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