test: validate Splunk_version using metricsTest reusable workflow branch (#205)

Validation for the Splunk version update is complete.

Tested the changes from the addonfactory-test-matrix-action PR by
running the reusable workflow against the Splunk Add-on for Apache Web
Server.

The test workflow passed successfully, and the logs confirm that the new
Splunk version was correctly picked up and used by the test matrix.

**Test Run link**
https://github.com/splunk/splunk-add-on-for-apache-web-server/actions/runs/22388067008

Author: poojpat2

action.yml

@@ -7,4 +7,4 @@ inputs:
     type: string
 runs:
   using: "docker"
-  image: docker://ghcr.io/splunk/addonfactory-test-matrix-action/addonfactory-test-matrix-action:v3.1.4
+  image: 'Dockerfile'

config/splunk_matrix.conf

@@ -10,22 +10,22 @@ PYTHON39 = true
 PYTHON37 = false
 
 [10.0]
-VERSION = 10.0.2
-BUILD = e2d18b4767e9
+VERSION = 10.0.3
+BUILD = adbac1c8811c
 SUPPORTED = 2027-07-28
 PYTHON39 = true
 PYTHON37 = false
 
 [9.4]
-VERSION = 9.4.7
-BUILD = 2a9293b80994
+VERSION = 9.4.8
+BUILD = c543277b24fa
 SUPPORTED = 2026-12-16
 PYTHON39 = true
 PYTHON37 = false
 
 [9.3]
-VERSION = 9.3.8
-BUILD = fbf0510dff69
+VERSION = 9.3.9
+BUILD = 305ee211181f
 SUPPORTED = 2026-07-24
 PYTHON39 = true
 PYTHON37 = false