tools: consistently use #!/usr/bin/env python3

It's ugly, but it's better to be consistently ugly.

.ycm_extra_conf.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # SPDX-License-Identifier: Unlicense
 #

src/fuzz/fuzz-bootspec-gen.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
 """Generate sample input for fuzz-bootspec"""

test/integration-tests/integration-test-wrapper.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
 """Test wrapper command for driving integration tests."""

tools/analyze-dump-sort.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 # SPDX-License-Identifier: LGPL-2.1-or-later
 # pylint: disable=consider-using-with
 

tools/check-efi-alignment.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
 # SPDX-License-Identifier: LGPL-2.1-or-later
 # vi: set tw=110 sw=4 ts=4 et:
 

tools/dump-auxv.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 # SPDX-License-Identifier: LGPL-2.1-or-later
 #
 # Note: the no-value-for-parameter here is expected, as the click module