E2E: update .gitignore files to avoid committing runtime files (#24855)

In #24694 we did a major refactoring of the E2E Terraform configuration. After
deploying a cluster this morning, I noticed a few moved/removed files were not
reflected in the .gitignore files. This changeset updates the .gitignore to have
no unstaged files after applying.

e2e/.gitignore

@@ -1 +0,0 @@
-provisioning.json

e2e/terraform/.gitignore

@@ -0,0 +1,2 @@
+custom.tfvars
+remotetasks/

e2e/terraform/provision-infra/.gitignore

@@ -1,3 +1,7 @@
 *.zip
-uploads/
 custom.tfvars
+
+# ephemeral objects added by module
+provision-nomad/uploads/
+keys/
+csi/