Bump docker/login-action from 1 to 2

Bumps [docker/login-action](https://github.com/docker/login-action) from 1 to 2.
- [Release notes](https://github.com/docker/login-action/releases)
- [Commits](docker/login-action@v1...v2)

---
updated-dependencies:
- dependency-name: docker/login-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
 
     # GITHUB_TOKEN is unreliable¹ so use a token from nextstrain-bot.
     # ¹ https://github.com/docker/build-push-action/issues/463#issuecomment-939394233
-    - uses: docker/login-action@v1
+    - uses: docker/login-action@v2
       with:
         registry: ghcr.io
         username: nextstrain-bot
@@ -56,7 +56,7 @@ jobs:
           - linux/arm64
     steps:
 
-    - uses: docker/login-action@v1
+    - uses: docker/login-action@v2
       with:
         registry: ghcr.io
         username: nextstrain-bot
@@ -86,13 +86,13 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - uses: docker/login-action@v1
+    - uses: docker/login-action@v2
       with:
         registry: ghcr.io
         username: nextstrain-bot
         password: ${{ secrets.GH_TOKEN_NEXTSTRAIN_BOT_MANAGE_PACKAGES }}
 
-    - uses: docker/login-action@v1
+    - uses: docker/login-action@v2
       with:
         registry: docker.io
         username: nextstrainbot
@@ -108,13 +108,13 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - uses: docker/login-action@v1
+    - uses: docker/login-action@v2
       with:
         registry: ghcr.io
         username: nextstrain-bot
         password: ${{ secrets.GH_TOKEN_NEXTSTRAIN_BOT_MANAGE_PACKAGES }}
 
-    - uses: docker/login-action@v1
+    - uses: docker/login-action@v2
       with:
         registry: docker.io
         username: nextstrainbot