chore: use test_key_1 instead of dfx_test_key in icp.yaml and canister tests

Standardise on the icp-cli/PocketIC key name now that dfx is no longer
used. The library retains backward-compatible handling of dfx_test_key
for existing deployments.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: marc0olo

backend/rs/canisters/ic_vetkeys_encrypted_maps_canister/tests/tests.rs

@@ -984,7 +984,7 @@ impl TestEnvironment {
         pic.install_canister(
             example_canister_id,
             example_wasm_bytes,
-            encode_one("dfx_test_key").unwrap(),
+            encode_one("test_key_1").unwrap(),
             None,
         );
 

backend/rs/canisters/ic_vetkeys_manager_canister/tests/tests.rs

@@ -531,7 +531,7 @@ impl TestEnvironment {
         pic.install_canister(
             example_canister_id,
             example_wasm_bytes,
-            encode_one("dfx_test_key").unwrap(),
+            encode_one("test_key_1").unwrap(),
             None,
         );
 

backend/rs/canisters/icp.yaml

@@ -7,7 +7,7 @@ canisters:
         candid: ic_vetkeys_manager_canister/ic_vetkeys_manager_canister.did
     init_args:
       type: text
-      value: "(\"dfx_test_key\")"
+      value: "(\"test_key_1\")"
   - name: ic_vetkeys_encrypted_maps_canister
     recipe:
       type: "@dfinity/rust@v3.2.0"
@@ -16,4 +16,4 @@ canisters:
         candid: ic_vetkeys_encrypted_maps_canister/ic_vetkeys_encrypted_maps_canister.did
     init_args:
       type: text
-      value: "(\"dfx_test_key\")"
+      value: "(\"test_key_1\")"

backend/rs/canisters/tests/tests/sign_with_bls.rs

@@ -14,7 +14,7 @@ fn bls_signature_should_be_valid_and_equal_to_decrypted_vetkey() {
     let context = random_bytes(rng, 10);
     let key_id = VetKDKeyId {
         curve: VetKDCurve::Bls12_381_G2,
-        name: "dfx_test_key".to_string(),
+        name: "test_key_1".to_string(),
     };
     let transport_secret_key = random_transport_key(rng);
     let transport_public_key = transport_secret_key.public_key();
@@ -56,7 +56,7 @@ fn bls_public_key_should_be_equal_to_verification_key() {
     let context = random_bytes(rng, 10);
     let key_id = VetKDKeyId {
         curve: VetKDCurve::Bls12_381_G2,
-        name: "dfx_test_key".to_string(),
+        name: "test_key_1".to_string(),
     };
     let bls_public_key: Vec<u8> = env.update(
         Principal::anonymous(),