MLBEDSW-7579: Fix test_build.py test issues

* Fix import order in test_build.py
* Fix setup_tools_scm dependency version. Previously the version was
  restricted to < 6, creating a version restriction on Setuptools
  library too.
  Because an older version of Setuptools was used, running
  test_build.py::test_build_correct_readme_links would generate a
  UNKNOWN.egg-info directory in the src directory instead of a
  ethos_u_vela.egg-info directory.

Change-Id: I113ca25b23b39d43fa288e6eda16377f4f5b4143
Signed-off-by: Raul Farkas <raul.farkas@arm.com>
diff --git a/ethosu/vela/test/test_build.py b/ethosu/vela/test/test_build.py
index f4a1cd0..5dd7fe1 100644
--- a/ethosu/vela/test/test_build.py
+++ b/ethosu/vela/test/test_build.py
@@ -20,7 +20,7 @@
 from tarfile import TarFile
 from tempfile import TemporaryDirectory
 
-import build
+import build  # noreorder
 import pytest
 
 
diff --git a/pyproject.toml b/pyproject.toml
index fbb7204..2127d1a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,7 +47,7 @@
     "pytest-cov",
     "pre-commit",
     "build",
-    "setuptools_scm[toml]<6"
+    "setuptools_scm[toml]~=7.1.0"
 ]
 
 [project.urls]
@@ -60,6 +60,6 @@
 requires = [
     "numpy<=1.21.3; python_version<='3.7'",
     "numpy; python_version>'3.7'",
-    "setuptools_scm[toml]<6"
+    "setuptools_scm[toml]~=7.1.0"
 ]
 build-backend = "setuptools.build_meta"
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