Revert "Update nightly tag every night (#17879)" (#18133)

This PR reverts #17879, as it wasn't working.

When a GitHub Action pushes a tag, it does not trigger workflows for
push events for that tag:

> When you use the repository's `GITHUB_TOKEN` to perform tasks, events
triggered by the `GITHUB_TOKEN`, with the exception of
`workflow_dispatch` and `repository_dispatch`, will not create a new
workflow run. This prevents you from accidentally creating recursive
workflow runs. For example, if a workflow run pushes code using the
repository's `GITHUB_TOKEN`, a new workflow will not run even when the
repository contains a workflow configured to run when `push` events
occur.
>
> —
[source](https://docs.github.com/en/actions/security-for-github-actions/security-guides/automatic-token-authentication#using-the-github_token-in-a-workflow)

This reverts commit 761129e373.

Release Notes:

- N/A

.github/workflows/bump_nightly_tag.yml

@@ -1,23 +0,0 @@
-name: Update Nightly Tag
-
-on:
-  schedule:
-    # Fire every day at 7:00am UTC (Roughly before EU workday and after US workday)
-    - cron: "0 7 * * *"
-
-jobs:
-  update-nightly-tag:
-    if: github.repository_owner == 'zed-industries'
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
-        with:
-          fetch-depth: 0
-
-      - name: Update nightly tag
-        run: |
-          git config user.name github-actions
-          git config user.email github-actions@github.com
-          git tag -f nightly
-          git push origin nightly --force

.github/workflows/release_nightly.yml

@@ -1,6 +1,9 @@
 name: Release Nightly
 
 on:
+  schedule:
+    # Fire every day at 7:00am UTC (Roughly before EU workday and after US workday)
+    - cron: "0 7 * * *"
   push:
     tags:
       - "nightly"