ci: limit concurrency

Signed-off-by: Unai Martinez-Corral <umartinezcorral@antmicro.com>

.github/workflows/Tests.yml

diff --git a/.github/workflows/Tests.yml b/.github/workflows/Tests.yml
index 87cd92c..1138d5d 100644
--- a/.github/workflows/Tests.yml
+++ b/.github/workflows/Tests.yml
@@ -14,6 +14,12 @@
 
 name: Regression testing
 
+# Prevent keeping resources busy when a branch/PR is updated
+# https://docs.github.com/en/actions/using-jobs/using-concurrency
+concurrency:
+  group: ${{ github.repository }}-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 on:
   push:
   pull_request: