[.github/workflow/rust.yml] Add docker credentials to avoid rate limit

To avoid errors such
```
Error toomanyrequests: You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limit
```

we should add login to our Scylladb docker hub

Adding it

Author: yaronkaikov

.github/workflows/authenticate_test.yml

@@ -31,3 +31,6 @@ jobs:
       run: rustup update
     - name: Run tests
       run: RUST_LOG=trace cargo test --verbose authenticate_superuser -- custom_authentication --ignored
+      env:
+        DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+        DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}

.github/workflows/book.yml

@@ -29,6 +29,9 @@ jobs:
     - uses: actions/checkout@v3
     - name: Update rust toolchain
       run: rustup update
+      env:
+        DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+        DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
     - name: Install mdbook
       run: cargo install mdbook --no-default-features
     - name: Build the project

.github/workflows/cassandra.yml

@@ -27,6 +27,9 @@ jobs:
       # A separate step for building to separate measuring time of compilation and testing
     - name: Update rust toolchain
       run: rustup update
+      env:
+        DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+        DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
     - name: Build the project
       run: cargo build --verbose --tests --features "full-serialization"
     - name: Run tests on cassandra

.github/workflows/rust.yml

@@ -26,6 +26,9 @@ jobs:
       run: |
         sudo sh -c "echo 2097152 >> /proc/sys/fs/aio-max-nr"
         docker compose -f test/cluster/docker-compose.yml up -d --wait
+      env:
+        DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+        DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
     - name: Update rust toolchain
       run: rustup update
     - name: Print rustc version

.github/workflows/tls.yml

@@ -34,6 +34,9 @@ jobs:
     - uses: actions/checkout@v3
     - name: Update rust toolchain
       run: rustup update
+      env:
+        DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+        DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
     - name: Check
       run: cargo check --verbose --features "ssl"
       working-directory: ${{env.working-directory}}