Remove nightly from CI

We do not get any benefit from running CI with the nightly toolchain.
We still run it with beta, so that should catch some errors if there are
any.

Signed-off-by: Matthias Beyer <[email protected]>

Author: matthiasbeyer

.github/workflows/msrv.yml

@@ -12,7 +12,6 @@ jobs:
           - 1.70.0
           - stable
           - beta
-          - nightly
 
     steps:
       - name: Checkout sources
@@ -27,12 +26,6 @@ jobs:
           toolchain: ${{ matrix.rust }}
 
       - name: Run cargo check
-        if: matrix.rust != 'nightly'
-        run: cargo check --all-features
-
-      - name: Run cargo check (nightly)
-        if: matrix.rust == 'nightly'
-        continue-on-error: true
         run: cargo check --all-features
 
   test:
@@ -45,7 +38,6 @@ jobs:
           - 1.70.0
           - stable
           - beta
-          - nightly
     steps:
       - name: Checkout sources
         uses: actions/[email protected]
@@ -59,17 +51,6 @@ jobs:
           toolchain: ${{ matrix.rust }}
 
       - name: Run cargo test
-        if: matrix.rust != 'nightly' && matrix.rust != '1.56.1'
-        run: cargo test --all-features
-
-      - name: Run cargo test (nightly)
-        if: matrix.rust == '1.66.0'
-        continue-on-error: true
-        run: cargo test --tests --all-features
-
-      - name: Run cargo test (nightly)
-        if: matrix.rust == 'nightly'
-        continue-on-error: true
         run: cargo test --all-features
 
   fmt: