Do not allow changing rust toolchain breaking our CI

Same as with the mutable "stable" being removed from our CI, we run beta
toolchain CI stuff, but we should no longer allow a changing beta
version break our CI "randomly".

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

Author: matthiasbeyer

.github/workflows/msrv.yml

@@ -26,6 +26,7 @@ jobs:
           toolchain: ${{ matrix.rust }}
 
       - name: Run cargo check
+        continue-on-error: ${{ matrix.rust == 'beta' }}
         run: cargo check --all-features
 
   test:
@@ -51,6 +52,7 @@ jobs:
           toolchain: ${{ matrix.rust }}
 
       - name: Run cargo test
+        continue-on-error: ${{ matrix.rust == 'beta' }}
         run: cargo test --all-features
 
   fmt:
@@ -73,6 +75,7 @@ jobs:
           components: rustfmt
 
       - name: Run cargo fmt
+        continue-on-error: ${{ matrix.rust == 'beta' }}
         run: cargo fmt --all -- --check
 
   clippy: