feat: Gate config cache on Git 2.54.0+ version check

Context:
The config cache uses 'git config list --type=<X>' to load
type-specific caches (raw, bool, path). The --type flag for the
'list' subcommand requires a fix queued for the Git 2.54.0
release. On Git 2.53 and earlier, the command succeeds but
silently ignores the --type parameter, returning raw values
instead of canonicalized ones. This means bool caches would
contain 'yes'/'on' instead of 'true', and path caches would
contain unexpanded '~/...' instead of absolute paths.

Justification:
Because the command exits 0 on older Git, the cache appears to
load successfully and the fallback paths never trigger. This makes
the bug silent and data-dependent: lookups work for values that
happen to already be in canonical form but return wrong results
for others. A version gate is the only reliable way to avoid this.

The check is in the constructor body rather than the constructor
chain so we can log a trace message when caching is disabled. The
explicit useCache parameter is preserved for tests that need to
control caching behavior independently of version.

Implementation:
Added ConfigListTypeMinVersion constant (2.54.0) and a version
comparison in the GitProcessConfiguration constructor. When
useCache is requested but git.Version is below the minimum, the
constructor overrides useCache to false and emits a trace line.
All existing fallback paths continue to work unchanged for users
on older Git, who will benefit from the cache automatically once
they upgrade.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: derrickstolee

src/shared/Core/GitConfiguration.cs

@@ -334,6 +334,7 @@ public void Clear()
     public class GitProcessConfiguration : IGitConfiguration
     {
         private static readonly GitVersion TypeConfigMinVersion = new GitVersion(2, 18, 0);
+        private static readonly GitVersion ConfigListTypeMinVersion = new GitVersion(2, 54, 0);
 
         private readonly ITrace _trace;
         private readonly GitProcess _git;
@@ -351,6 +352,14 @@ internal GitProcessConfiguration(ITrace trace, GitProcess git, bool useCache)
 
             _trace = trace;
             _git = git;
+
+            // 'git config list --type=<X>' requires Git 2.54.0+
+            if (useCache && git.Version < ConfigListTypeMinVersion)
+            {
+                trace.WriteLine($"Git version {git.Version} is below {ConfigListTypeMinVersion}; config cache disabled");
+                useCache = false;
+            }
+
             _useCache = useCache;
             _cache = useCache ? new Dictionary<GitConfigurationType, ConfigCache>() : null;
         }