Reduce concurrency level of hs_extended.jck in Windows

The hs_extended.jck test in Windows / x86_64 has been running for more than one day [1].

A quick look at the log of the (still running) process shows that `jck-compiler-lang-LMBD_0` took about six hours to complete.

A more detailed look at the log file shows that this test is running with `concurrency` set to `5`:

```
[2026-04-24T06:07:02.978Z] >>>>>>>>>>
[2026-04-24T06:07:02.978Z] testsuite "C:\\Users\\jenkins\\jck_root\\JCK25-unzipped\\JCK-compiler-25";
[2026-04-24T06:07:02.978Z] workDirectory -create C:/Users/jenkins/workspace/Test_openjdk25_hs_extended.jck_x86-64_windows_testList_1/aqa-tests/\\TKG\\output_17769177972049\\jck-compiler-lang-PKGS_0\\work;
[2026-04-24T06:07:02.978Z] tests lang/PKGS;
[2026-04-24T06:07:02.978Z] concurrency 5;
[2026-04-24T06:07:02.978Z] timeoutfactor 100;
[2026-04-24T06:07:02.978Z] keywords compiler;
[2026-04-24T06:07:02.978Z] runTests;
[2026-04-24T06:07:02.978Z] writeReport -type xml C:/Users/jenkins/workspace/Test_openjdk25_hs_extended.jck_x86-64_windows_testList_1/aqa-tests/\\TKG\\output_17769177972049\\jck-compiler-lang-PKGS_0\\report;
[2026-04-24T06:07:02.979Z] <<<<<<<<
```

What happens is that **if too many JVMs are launched at the same time, they fight each other for CPU resources, and the net result is that no JVM is able to end the job**. So basically the test is testing the operating system capability to do context/task switching.

In the past (see https://github.com/adoptium/aqa-tests/issues/6762) we already changed `concurrency` to `1`. It would be great if we could reduce the current `concurrency` setting for at least the following tests:

- `jck-compiler-lang-LMBD_0`
- `jck-compiler-lang-PKGS_0`
- `jck-compiler-lang-MOD_0`

From the following listing:

Timings of `Test_openjdk25_hs_extended.jck_x86-64_windows_testList_1_35.log` (note total duration of `1550` minutes (that's 25 hours).

| Test | Duration (min) | Start | End |
| ---- | -------------- | ----- | --- |
| jck-compiler-lang-LMBD_0 | 341.31 | 2026-04-23 16:03:18.490000+00:00 | 2026-04-23 21:44:37.160000+00:00 |
| jck-compiler-lang-MOD_0 | 212.76 | 2026-04-24 02:34:10.622000+00:00 | 2026-04-24 06:06:56.040000+00:00 |
| jck-compiler-lang-DASG_0 | 144.11 | 2026-04-23 21:44:43.360000+00:00 | 2026-04-24 00:08:50.108000+00:00 |
| jck-compiler-lang-CLSS-Group10_0 | 118.57 | 2026-04-23 07:45:16.741000+00:00 | 2026-04-23 09:43:50.928000+00:00 |
| jck-compiler-lang-EXPR-group11_0 | 118.31 | 2026-04-23 14:04:56.001000+00:00 | 2026-04-23 16:03:14.381000+00:00 |
| jck-compiler-lang-ICLS_0 | 111.45 | 2026-04-24 00:42:43.457000+00:00 | 2026-04-24 02:34:10.329000+00:00 |
| jck-compiler-lang-EXPR-group7_0 | 86.79 | 2026-04-23 11:37:41.591000+00:00 | 2026-04-23 13:04:28.794000+00:00 |
| jck-compiler-lang-CLSS-Group8_0 | 74.34 | 2026-04-23 06:30:55.707000+00:00 | 2026-04-23 07:45:16.294000+00:00 |
| jck-compiler-lang-EXPR-group9_0 | 60.41 | 2026-04-23 13:04:31.103000+00:00 | 2026-04-23 14:04:55.790000+00:00 |
| jck-compiler-lang-BINC_0 | 56.35 | 2026-04-23 04:28:31.839000+00:00 | 2026-04-23 05:24:53.132000+00:00 |
| jck-compiler-lang-EXPR-group1_0 | 46.22 | 2026-04-23 09:43:55.500000+00:00 | 2026-04-23 10:30:08.917000+00:00 |
| jck-compiler-lang-EXPR-group3_0 | 44.75 | 2026-04-23 10:30:11.698000+00:00 | 2026-04-23 11:14:56.414000+00:00 |
| jck-compiler-lang-EXEC_0 | 33.81 | 2026-04-24 00:08:54.696000+00:00 | 2026-04-24 00:42:43.455000+00:00 |
| jck-compiler-lang-CLSS-Group4_0 | 31.95 | 2026-04-23 05:40:51.762000+00:00 | 2026-04-23 06:12:48.872000+00:00 |
| jck-compiler-lang-EXPR-group5_0 | 22.75 | 2026-04-23 11:14:56.643000+00:00 | 2026-04-23 11:37:41.589000+00:00 |
| jck-compiler-lang-CLSS-Group6_0 | 18.03 | 2026-04-23 06:12:51.633000+00:00 | 2026-04-23 06:30:53.504000+00:00 |
| jck-compiler-lang-CLSS-Group2_0 | 15.96 | 2026-04-23 05:24:54.252000+00:00 | 2026-04-23 05:40:51.761000+00:00 |
| jck-compiler-api-javax_lang_0 | 11.87 | 2026-04-23 04:16:39.499000+00:00 | 2026-04-23 04:28:31.837000+00:00 |
| TOTAL | 1549.75 | 2026-04-23 04:16:39.499000+00:00 | 2026-04-24 06:06:56.040000+00:00 |

[1]
https://ci.eclipse.org/temurin-compliance/job/Test_openjdk25_hs_extended.jck_x86-64_windows_testList_1/35

Locate the configuration that generates the Windows x86_64 hs_extended.jck entries, using the three named tests and issue 6762 as references. Reduce their concurrency settings and verify that the generated JCK logs show the intended value for LMBD, PKGS, and MOD without the extended runtime seen in the linked CI job.

Written by the indexing model from the issue text.