Migrate from GitHub HashiBot to GitHub Actions

Replaces the only enabled behavior with an equivalent workflow.

.github/workflows/lock.yml

+name: 'Lock Threads'
+
+on:
+  schedule:
+    - cron: '50 1 * * *'
+
+jobs:
+  lock:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: dessant/lock-threads@v2
+        with:
+          github-token: ${{ github.token }}
+          issue-lock-comment: >
+            I'm going to lock this issue because it has been closed for _30 days_ ⏳. This helps our maintainers find and focus on the active issues.
+
+            If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.
+          issue-lock-inactive-days: '30'
+          pr-lock-comment: >
+            I'm going to lock this pull request because it has been closed for _30 days_ ⏳. This helps our maintainers find and focus on the active issues.
+
+            If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.
+          pr-lock-inactive-days: '30'

.hashibot.hcl

-poll "closed_issue_locker" "locker" {
-  schedule             = "0 50 1 * * *"
-  closed_for           = "720h" # 30 days
-  max_issues           = 500
-  sleep_between_issues = "5s"
-
-  no_comment_if_no_activity_for = "4320h" # 180 days
-
-  message = <<-EOF
-    I'm going to lock this issue because it has been closed for _30 days_ ⏳. This helps our maintainers find and focus on the active issues.
-
-    If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.
-  EOF
-}