ci: note ordering constraint on transitive patch step

Document that the transitive [patch.crates-io] step must run after the
spec-shaking step, so the spec-shaking sed does not add an ignored features
field to the patch entries.

Author: leighmcculloch

.github/workflows/test-with-openzeppelin-stellar-contracts.yml

@@ -96,6 +96,10 @@ jobs:
         # Add features field to path-patched entries without features
         sed -i '/soroban-sdk = {.*path = /{/features/!s| }|, features = ["experimental_spec_shaking_v2"] }|}' Cargo.toml
 
+    # This step must run *after* "Enable experimental_spec_shaking_v2": that step's
+    # sed matches every `soroban-sdk = { ... path = ... }` line, so if the
+    # [patch.crates-io] entries below already existed it would add a `features` field
+    # to them, which Cargo ignores on patch entries and warns about.
     - name: Patch transitive crates.io dependencies
       working-directory: stellar-contracts
       run: |

.github/workflows/test-with-soroban-examples.yml

@@ -112,6 +112,10 @@ jobs:
           sed -i '/soroban-sdk = {.*path = /{/features/!s| }|, features = ["experimental_spec_shaking_v2"] }|}' "$file"
         done
 
+    # This step must run *after* "Enable experimental_spec_shaking_v2": that step's
+    # sed matches every `soroban-sdk = { ... path = ... }` line, so if the
+    # [patch.crates-io] entries below already existed it would add a `features` field
+    # to them, which Cargo ignores on patch entries and warns about.
     - name: Patch transitive crates.io dependencies
       run: |
         # Crates such as soroban-poseidon are pulled from crates.io and depend on