In io-lifetimes to 1.0.6 when using Rust 1.48.

io-lifetimes 1.0.7 has a dependency on hermit-abi which doesn't affect
normal builds but does affect cargo tree, which is used in some of
rustix's tests.

.github/workflows/main.yml

@@ -88,7 +88,14 @@ jobs:
 
     - name: Use specific dependency versions for Rust 1.48 compatibility.
       if: matrix.rust == '1.48'
-      run: cargo update --package=once_cell --precise 1.14.0
+      run: |
+        cargo update --package=once_cell --precise 1.14.0
+        cargo update --package=io-lifetimes --precise 1.0.6
+        for crate in test-crates/*; do
+            cd $crate
+            cargo update --package=io-lifetimes --precise 1.0.6
+            cd - >/dev/null
+        done
 
     - run: cargo check --workspace --release -vv --all-targets
     - run: cargo check --workspace --release -vv --features=all-apis --all-targets
@@ -518,7 +525,14 @@ jobs:
 
     - name: Use specific dependency versions for Rust 1.48 compatibility.
       if: matrix.rust == '1.48'
-      run: cargo update --package=once_cell --precise 1.14.0
+      run: |
+        cargo update --package=once_cell --precise 1.14.0
+        cargo update --package=io-lifetimes --precise 1.0.6
+        for crate in test-crates/*; do
+            cd $crate
+            cargo update --package=io-lifetimes --precise 1.0.6
+            cd - >/dev/null
+        done
 
     - run: |
         # Run the tests, and check the prebuilt release libraries.