Support MSRV 1.60 and re-organize into workspace

Author: tomtomwombat

.github/workflows/rust.yml

@@ -19,29 +19,20 @@ jobs:
     - name: Install cargo-hack
       run: cargo install cargo-hack
     - name: Build
-      run: cargo hack build --verbose --release --feature-powerset
+      run: cargo hack build --manifest-path cold-string/Cargo.toml --verbose --release --feature-powerset --version-range 1.60..
+    - name: Check
+      run: cargo hack check --manifest-path cold-string/Cargo.toml --verbose --release --feature-powerset --version-range 1.60..
+    - name: Test No Exposed Provenance
+      run: cargo +1.74 hack test --manifest-path cold-string/Cargo.toml --verbose --release --feature-powerset
     - name: Tests
-      run: cargo hack test --verbose --release --feature-powerset
+      run: cargo hack test --manifest-path cold-string/Cargo.toml --verbose --release --feature-powerset
     - name: Install nightly + Miri
       run: |
           rustup toolchain install nightly
           rustup component add miri --toolchain nightly
     - name: Run Miri
       run: |
-          cargo +nightly miri test --test property
+          cargo +nightly miri test --manifest-path cold-string/Cargo.toml --test property
     - name: Run Miri Unknown
       run: |
-          cargo +nightly miri test --test property --target mips-unknown-linux-gnu
-  msrv:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: "1.84"
-          override: true
-      - name: Install cargo-hack
-        run: cargo +1.84 install cargo-hack --version 0.6.37 --force --locked
-      - name: Build
-        run: cargo +1.84 hack build --verbose --release --feature-powerset
-
+          cargo +nightly miri test --manifest-path cold-string/Cargo.toml --test property --target mips-unknown-linux-gnu