ci: changed from actions-rs to a more maintained CI alternative (#188)

In CI, we are currently using `actions-rs` variant of steps. [They are
pretty deprecated.](https://github.com/actions-rs)
This resolves these, which I noticed during #186's [actions
run](https://github.com/testcontainers/testcontainers-rs-modules-community/actions/runs/10481678682?pr=186):


![image](https://github.com/user-attachments/assets/26f6a040-314e-4183-bec9-0b0a03701b32)

There are a ton of options avaliable, maybe even a `rust-lang`-action
rust-lang/rustup#3409
Currently, that is not the case.
(open to alternatives if you prefer another one more ^^)

> [!NOTE]
> This is not without downside as replacing `uses: actions-rs/cargo`
with `run: cargo ...` does not come with the annotations that github
displays f. ex. here from another repo where I recently also contributed
this:
>
![image](https://github.com/user-attachments/assets/6b61c970-800d-4489-8433-bd5df44bc5fa)
> Said annotation would still be shown, but only as a test failour and
not inline..

I have also added the nightly rustfmt part ^^

.github/workflows/ci.yml

@@ -46,37 +46,24 @@ jobs:
     steps:
       - name: Checkout sources
         uses: actions/checkout@v4
-      - uses: Swatinem/rust-cache@v2
-      - uses: actions-rs/toolchain@v1
+      - uses: actions-rust-lang/[email protected]
         with:
-          profile: minimal
           toolchain: stable
           components: clippy
-          override: true
       - name: Clippy check
-        uses: actions-rs/clippy-check@v1
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features
+        run: cargo clippy --all-features
 
   fmt:
     name: Rustfmt check
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
         uses: actions/checkout@v4
-      - uses: Swatinem/rust-cache@v2
-      - uses: actions-rs/toolchain@v1
+      - uses: actions-rust-lang/[email protected]
         with:
-          profile: minimal
-          toolchain: stable
+          toolchain: nightly
           components: rustfmt
-          override: true
-      - name: Rustfmt check
-        uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: --all -- --check
+      - run: cargo +nightly fmt --all -- --check
 
   prlint:
     name: PR name check