ci: Runner now uses Swift 6.1; update the Static SDK to match (#79)

Motivation
----------

End to end and integration tests are failing because the underlying
Swift CI runner has been updated to use Swift 6.1 but these tests
install the 6.0.2 release of the Static Linux SDK.

Modifications
-------------

Update end to end and integration workflows to install the the 6.1
release of the Static Linux SDK.

Result
------

All tests will pass again.

Test Plan
---------

All existing tests pass again.

Author: euanh

.github/workflows/endtoend_tests.yml

@@ -34,8 +34,8 @@ jobs:
             - name: Install the static SDK
               run: |
                   swift sdk install \
-                      https://download.swift.org/swift-6.0.2-release/static-sdk/swift-6.0.2-RELEASE/swift-6.0.2-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz \
-                      --checksum aa5515476a403797223fc2aad4ca0c3bf83995d5427fb297cab1d93c68cee075
+                      https://download.swift.org/swift-6.1-release/static-sdk/swift-6.1-RELEASE/swift-6.1-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz \
+                      --checksum 111c6f7d280a651208b8c74c0521dd99365d785c1976a6e23162f55f65379ac6
 
             - name: Build the example
               run: |

.github/workflows/interop_tests.yml

@@ -65,8 +65,8 @@ jobs:
             - name: Install the static SDK
               run: |
                   swift sdk install \
-                      https://download.swift.org/swift-6.0.2-release/static-sdk/swift-6.0.2-RELEASE/swift-6.0.2-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz \
-                      --checksum aa5515476a403797223fc2aad4ca0c3bf83995d5427fb297cab1d93c68cee075
+                      https://download.swift.org/swift-6.1-release/static-sdk/swift-6.1-RELEASE/swift-6.1-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz \
+                      --checksum 111c6f7d280a651208b8c74c0521dd99365d785c1976a6e23162f55f65379ac6
 
             # Run the test script
             - name: Test ELF detection