Change kmir branch from master to release (#139)

Author: juliankuners

src/kup/__main__.py

@@ -64,7 +64,7 @@
     GithubPackage('runtimeverification', 'avm-semantics', PackageName('kavm')),
     GithubPackage('runtimeverification', 'evm-semantics', PackageName('kevm'), branch='release'),
     GithubPackage('runtimeverification', 'plutus-core-semantics', PackageName('kplutus')),
-    GithubPackage('runtimeverification', 'mir-semantics', PackageName('kmir')),
+    GithubPackage('runtimeverification', 'mir-semantics', PackageName('kmir'), branch='release'),
     GithubPackage('runtimeverification', 'kontrol', PackageName('kontrol'), branch='release'),
     GithubPackage('runtimeverification', 'kasmer-multiversx', PackageName('kmxwasm')),
     GithubPackage('runtimeverification', 'komet', PackageName('komet')),