CI: Reduce pip behaviour dependencies in test suite

.gitignore

@@ -2,6 +2,7 @@
 *.t.err
 
 # Python cruft
+__pycache__
 *.pyc
 
 # Virtualenvs

tests/test_cli_compile.py

@@ -3428,10 +3428,21 @@ def test_compile_recursive_extras_build_targets(runner, tmp_path, current_resolv
             [project.optional-dependencies]
             footest = ["small-fake-b"]
             dev = ["foo[footest]"]
+            [build-system]
+            requires = ["setuptools == 70.0.0"]
+            build-backend = "setuptools.build_meta"
             """
         )
     )
-    (tmp_path / "constraints.txt").write_text("wheel<0.43")
+    version_constraints = [
+        "setuptools<70.1.0",
+        "wheel<0.43",
+    ]
+    constraints_file = tmp_path / "constraints.txt"
+    constraints_file.write_text("\n".join(version_constraints))
+    env = os.environ.copy()  # Copy entire env to avoid Windows compatibility issues
+    # Work around https://github.com/jazzband/pip-tools/pull/1681/files#r1667748889
+    env["PIP_CONSTRAINT"] = str(constraints_file)
     out = runner.invoke(
         cli,
         [
@@ -3451,6 +3462,7 @@ def test_compile_recursive_extras_build_targets(runner, tmp_path, current_resolv
             "--output-file",
             "-",
         ],
+        env=env,
     )
     expected = rf"""foo[footest] @ {tmp_path.as_uri()}
 small-fake-a==0.2

tests/test_sync.py

@@ -168,10 +168,7 @@ def test_diff_should_not_uninstall(fake_dist):
         "pip-tools==1.1.1",
         "pip-review==1.1.1",
         "pkg-resources==0.0.0",
-        "setuptools==34.0.0",
-        "wheel==0.29.0",
         "python==3.0",
-        "distribute==0.1",
         "wsgiref==0.1",
         "argparse==0.1",
     )