baas2: Same encoding string everywhere

While "utf8" works it seems python docs in general talks about "utf-8"
and it is what we are using in all other places in the code so make this
the same also.

files/baas2/sunet-baas2-bootstrap

@@ -80,7 +80,7 @@ def get_installed_version() -> Union[str, None]:
             check=True,
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
-            encoding="utf8",
+            encoding="utf-8",
         )
     except subprocess.CalledProcessError as exc:
         # If the package is not installed this is OK, we will install it

files/baas2/sunet-baas2-tbmr-bootstrap

@@ -52,7 +52,7 @@ def get_installed_version() -> Union[str, None]:
             check=True,
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
-            encoding="utf8",
+            encoding="utf-8",
         )
     except subprocess.CalledProcessError as exc:
         # If the package is not installed this is OK, we will install it