task: Use arbitrary long timeout instead of zero

The commentary explains the reasoning.

It's not expected to be an issue for Konflux, but theoretically
RHTAP users might have an older EC base image and could some day
migrate to this task definition which would break the task.

Decided to keep the commit separate rather than squash so we can
easily revert it some day.

Ref: https://issues.redhat.com/browse/EC-1030

features/task_validate_image.feature

@@ -316,7 +316,7 @@ Feature: Verify Enterprise Contract Tekton Tasks
       | IGNORE_REKOR         | true                                                                   |
       | TIMEOUT              | 666s                                                                   |
     Then the task should succeed
-      And the task logs for step "debug-log" should contain "globalTimeout is 0, no timeout used"
+      And the task logs for step "debug-log" should contain "globalTimeout is 100h0m0s"
 
   Scenario: SSL_CERT_DIR environment variable is customized
     Given a working namespace

tasks/verify-enterprise-contract/0.1/verify-enterprise-contract.yaml

@@ -226,8 +226,11 @@ spec:
         - "$(params.WORKERS)"
         # NOTE: The syntax below is required to negate boolean parameters
         - "--info=$(params.INFO)"
-        # No timeout for EC, though Tekton may apply a timeout
-        - "--timeout=0"
+        # Fresh versions of ec support "--timeout=0" to indicate no timeout, but this would break
+        # the task if it's used with an older version of ec. In an abundance of caution, let's set
+        # an arbitrary high value instead of using 0 here. In future we can change it to 0.
+        # (The reason to not use an explicit timeout for ec is so Tekton can handle the timeouts).
+        - "--timeout=100h"
         - "--strict=false"
         - "--show-successes"
         - "--effective-time=$(params.EFFECTIVE_TIME)"