manually install terraform in ubuntu-latest

ubuntu-latest is now Ubuntu 24.04 and terraform CLI is not
installed anymore.
See https://github.com/actions/runner-images/blob/ubuntu24/20250105.1/images/ubuntu/Ubuntu2404-Readme.md

The manual step requires manual updates to Terraform version
but avoids similar scenarios in the future

.github/workflows/functional-tests.yml

@@ -11,10 +11,11 @@ permissions:
   id-token: write
 
 env:
-    TF_VAR_BRANCH: ${{ github.ref_name }}
-    TF_VAR_BUILD_ID: ${{ github.run_id }}
-    TF_VAR_ENVIRONMENT: 'ci'
-    TF_VAR_REPO: ${{ github.repository }}
+  TF_VAR_BRANCH: ${{ github.ref_name }}
+  TF_VAR_BUILD_ID: ${{ github.run_id }}
+  TF_VAR_ENVIRONMENT: 'ci'
+  TF_VAR_REPO: ${{ github.repository }}
+  TERRAFORM_VERSION: 1.10.2
 
 jobs:
   run:
@@ -28,6 +29,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - uses: hashicorp/setup-terraform@b9cd54a3c349d3f38e8881555d616ced269862dd # v3.1.2
+        with:
+          terraform_version: "${{ env.TERRAFORM_VERSION }}"
+
       - uses: actions/setup-go@v5
         with:
           go-version-file: 'functionaltests/go.mod'