Improve performance of caching

### Brief Issue Summary

As soon as CMake Tools is done with configuring the project, it crashes the extension host.
The same happens if I use an already-configured configuration, where it only needs to read the cache.
I haven't been able to get much details, so any hints on how to provide extra information is welcome.

### CMake Tools Diagnostics

```shell
{
"os": "win32",
"vscodeVersion": "1.93.1",
"cmtVersion": "1.19.52",
"configurations": [
{
"folder": "e:\\Mega\\main",
"cmakeVersion": "3.30.2",
"configured": false,
"generator": "Ninja",
"usesPresets": true,
"compilers": {}
}
],
"cpptoolsIntegration": {
"isReady": false,
"hasCodeModel": false,
"activeBuildType": "",
"buildTypesSeen": [],
"requests": [],
"responses": [],
"partialMatches": [],
"targetCount": 0,
"executablesCount": 0,
"librariesCount": 0,
"targets": []
},
"settings": [
{
"communicationMode": "automatic",
"useCMakePresets": "always",
"configureOnOpen": true
}
]
}
```
```

### Debug Log

```shell
I used trace instead of debug as log level

[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake] Checking for new versions of NuGet packages with floating version...
[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake] Temporary project with all NuGet packages was not modified.
[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake]
[cmake] Restoring .\build\nuget\nuget-dependencies.csproj
[kit] Not reading non-existent kits file: e:\Mega\main\.vscode\cmake-kits.json
[rollbar] Invoking async function [] with Rollbar wrapping [Reloading variants file e:\Mega\main\compile_flags.txt]
[variant] Invalid variants specified:
[variant] >> : should be object
[variant] Loaded default variants
[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake] NuGet restore is not required.
[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake] -- Configuring done (29.1s)
[extension] [4667] cmake.logDiagnostics started
[extension] [4667] cmake.logDiagnostics finished (returned undefined)
[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake] -- Generating done (67.5s)
[rollbar] Invoking function [$] with Rollbar wrapping [$Processing "data" event from proc stdout]
[cmake] -- Build files have been written to: E:/Mega/main/.out/asan-clangcl
[rollbar] Invoking function [$] with Rollbar wrapping [$Resolving process on "close" event]
[cmakefileapi-driver]
[cmakefileapi-driver] Checking for new versions of NuGet packages with floating version...
Temporary project with all NuGet packages was not modified.

Restoring .\build\nuget\nuget-dependencies.csproj
NuGet restore is not required.
-- Configuring done (29.1s)
-- Generating done (67.5s)
-- Build files have been written to: E:/Mega/main/.out/asan-clangcl

[cmakefileapi-parser] Read reply folder: E:\Mega\main\.out\asan-clangcl\.cmake\api\v1\reply
[cmakefileapi-parser] Found index files: ["cache-v2-df5af9cfa1bf6faef9ac.json","cmakeFiles-v1-b69ee9cd2ad46d595f75.json" ...
[rollbar] Invoking async function [] with Rollbar wrapping [Update code model for cpptools]
[extension] Not updating the configuration provider because "C_Cpp.intelliSenseEngine" is set to "Disabled"
```
```

### Additional Information

_No response_

The payload names no source file or test. Begin by reproducing the crash after configuration and during cache-only startup, then inspect the cmakefileapi-parser path handling the .cmake/api/v1/reply cache-v2 JSON shown in the trace. Done means the extension host remains stable in both scenarios.

Written by the indexing model from the issue text.