Prefer getenv to env.get (#1568)

private/extensions/maven.bzl

diff --git a/private/extensions/maven.bzl b/private/extensions/maven.bzl
index d043afa..2ea955b 100644
--- a/private/extensions/maven.bzl
+++ b/private/extensions/maven.bzl
@@ -604,9 +604,8 @@
     # Second pass: merge and deduplicate repositories
     all_repo_names = {name: True for name in root_module_repos.keys() + non_root_module_repos.keys()}.keys()
 
-    os_env = mctx.os.environ
-    repin_env_var = os_env.get("REPIN")
-    rje_verbose_env_var = os_env.get("RJE_VERBOSE")
+    repin_env_var = mctx.getenv("REPIN")
+    rje_verbose_env_var = mctx.getenv("RJE_VERBOSE")
 
     for repo_name in all_repo_names:
         root_repo = root_module_repos.get(repo_name, {})

private/rules/coursier.bzl

diff --git a/private/rules/coursier.bzl b/private/rules/coursier.bzl
index f1be5a6..ba1cd0c 100644
--- a/private/rules/coursier.bzl
+++ b/private/rules/coursier.bzl
@@ -539,8 +539,9 @@
     )
 
 def is_repin_required(repository_ctx):
-    env_var_names = repository_ctx.os.environ.keys()
-    return "RULES_JVM_EXTERNAL_REPIN" not in env_var_names and "REPIN" not in env_var_names
+    repin_env_var = repository_ctx.getenv("REPIN")
+    rules_jvm_external_repin_env_var = repository_ctx.getenv("RULES_JVM_EXTERNAL_REPIN")
+    return rules_jvm_external_repin_env_var == None and repin_env_var == None
 
 def _get_fail_if_repin_required(repository_ctx):
     if not repository_ctx.attr.fail_if_repin_required: