Run Miri once everywhere it ran, not only on pull requests

The nightly musl matrix ran Miri in all eight of its entries, on the same pools
the pull request matrix was freed from. Its `TARGET_TRIPLE` never reaches the
recipe, which builds for the host with plain cargo, and the toolchain it pins
is the same one every other job uses, so the eight runs covered what one does.

The aarch64 daily run waited on the guest builds before starting. Miri reads no
guest binary, so it now waits for nothing and reports even when they fail.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Jorge Prendes <jorge.prendes@gmail.com>

Author: jprendes

.github/workflows/DailyArm64.yml

@@ -37,9 +37,10 @@ jobs:
       arch: arm64
       config: ${{ matrix.config }}
 
-  # Miri on aarch64, which the build-and-test matrix no longer carries.
+  # Miri on aarch64, which the build-and-test matrix no longer carries. It
+  # reads no guest binaries, so it waits for nothing and reports even when the
+  # guests fail to build.
   miri:
-    needs: build-guests
     uses: ./.github/workflows/dep_miri.yml
     secrets: inherit
     with:

.github/workflows/RustNightly.yml

@@ -98,14 +98,6 @@ jobs:
       - name: Build
         run: just build ${{ matrix.config }}
 
-      - name: Install cargo-nextest
-        uses: taiki-e/install-action@4cef1412cce204788f482e778a0b9187f9626a29  # v2.87.21
-        with:
-          tool: cargo-nextest
-
-      - name: Run Miri tests
-        run: env -u RUSTC_WRAPPER just miri-tests
-
       - name: Run Rust tests
         run: |
           # with default features
@@ -140,10 +132,18 @@ jobs:
           RUST_LOG: debug
         run: just test-rust-tracing ${{ matrix.config }}
 
+  # Miri asks nothing of a runner beyond its architecture, so it runs once on a
+  # hosted one rather than in every entry of the musl matrix.
+  miri:
+    uses: ./.github/workflows/dep_miri.yml
+    secrets: inherit
+    with:
+      arch: X64
+
   notify-failure:
     runs-on: ubuntu-latest
-    needs: musl
-    if: always() && needs.musl.result == 'failure'
+    needs: [musl, miri]
+    if: always() && (needs.musl.result == 'failure' || needs.miri.result == 'failure')
     permissions:
       issues: write
     steps: