test(NODE-6745): only find python when installing native (#4422)

Author: durran

.evergreen/config.yml

@@ -1534,6 +1534,11 @@ tasks:
       - auth
       - kerberos
     commands:
+      - command: expansions.update
+        type: setup
+        params:
+          updates:
+            - {key: NATIVE, value: 'true'}
       - func: install dependencies
       - func: run kerberos tests
   - name: test-auth-ldap

.evergreen/generate_evergreen_tasks.js

@@ -162,7 +162,13 @@ TASKS.push(
     {
       name: 'test-auth-kerberos',
       tags: ['auth', 'kerberos'],
-      commands: [{ func: 'install dependencies' }, { func: 'run kerberos tests' }]
+      commands: [
+        updateExpansions({
+          NATIVE: 'true'
+        }),
+        { func: 'install dependencies' },
+        { func: 'run kerberos tests' }
+      ]   
     },
     {
       name: 'test-auth-ldap',

.evergreen/install-dependencies.sh

@@ -11,6 +11,13 @@ export NODE_LTS_VERSION=${NODE_LTS_VERSION:-16}
 # be handled by this script in drivers tools.
 source $DRIVERS_TOOLS/.evergreen/install-node.sh
 
+if [ "$NATIVE" = "true" ]; then
+  # https://github.com/nodejs/node-gyp#configuring-python-dependency
+  . $DRIVERS_TOOLS/.evergreen/find-python3.sh
+  NODE_GYP_FORCE_PYTHON=$(find_python3)
+  export NODE_GYP_FORCE_PYTHON
+fi
+
 npm install "${NPM_OPTIONS}"
 
 source $DRIVERS_TOOLS/.evergreen/init-node-and-npm-env.sh