Run tests only on x86_64

Tests are intended to work only on x86_64. Other arches are tested in
the upstream.

Resolves: RHEL-32133

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

plans/integration-tests.fmf

@@ -8,3 +8,5 @@ discover:
     filter: tag:integration-test
 execute:
     how: tmt
+provision:
+    arch: x86_64

plans/unit-tests.fmf

@@ -11,3 +11,5 @@ discover:
     filter: tag:unit-test
 execute:
     how: tmt
+provision:
+    arch: x86_64

tests/image-build/build-images.sh

@@ -11,7 +11,9 @@ fi
 # ensure that we are running on x86_64 architecture
 if [ "$(uname -m)" != "x86_64" ]; then
     echo "Error: this script is only supported on x86_64 architecture"
-    exit 1
+    # NB: we are not failing here, because Testing Farm ignores the 'arch' field in the test plan spec
+    # See https://docs.testing-farm.io/Testing%20Farm/0.1/test-request.html#architectures
+    exit 0
 fi
 
 . /etc/os-release

tests/unit-tests/run-unit-tests.sh

@@ -5,6 +5,14 @@ set -euxo pipefail
 
 source /etc/os-release
 
+# ensure that we are running on x86_64 architecture
+if [ "$(uname -m)" != "x86_64" ]; then
+    echo "Error: this script is only supported on x86_64 architecture"
+    # NB: we are not failing here, because Testing Farm ignores the 'arch' field in the test plan spec
+    # See https://docs.testing-farm.io/Testing%20Farm/0.1/test-request.html#architectures
+    exit 0
+fi
+
 # The 'test/run/test_assemblers.py::test_tar' test case uses system tar to extract the built tar archive.
 # However, files in the tar archive can have SELinux context not present in the system policy. Therefore,
 # in order for the system tar to be able to set it when extracting the archive, it must be labeled with