tests: Skip some more snapshot tests on Python 3.7

The latest versions of Textual only support Python 3.8 and higher, so
differences from the snapshot are expected when running Python 3.7.

Signed-off-by: Matt Wozniski <mwozniski@bloomberg.net>

Author: godlygeek

tests/unit/test_tree_reporter.py

@@ -1561,6 +1561,10 @@ def compare_impl(
 
 
 class TestTUILooks:
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_basic(self, compare):
         # GIVEN
         code = dedent(
@@ -1633,6 +1637,10 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 2])
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_basic_node_selected_leaf(self, compare):
         # GIVEN
         code = dedent(
@@ -1667,6 +1675,10 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 3])
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_two_chains(self, compare):
         # GIVEN
         code = dedent(
@@ -1767,6 +1779,10 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 4, "e"])
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_hide_import_system(self, compare):
         # GIVEN
         code = dedent(
@@ -1817,6 +1833,10 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=["i"])
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_show_uninteresting(self, compare):
         # GIVEN
         code = dedent(
@@ -1867,6 +1887,10 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=["u"])
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_show_uninteresting_and_hide_import_system(self, compare):
         # GIVEN
         code = dedent(
@@ -1955,6 +1979,10 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 3])
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_allocations_of_different_sizes(self, compare):
         # GIVEN
         peak_allocations = [
@@ -1975,6 +2003,10 @@ def test_allocations_of_different_sizes(self, compare):
             getlines.return_value = []
             assert compare(peak_allocations, press=[], terminal_size=(350, 100))
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
+    )
     def test_biggest_allocations(self, compare):
         # GIVEN
         peak_allocations = [