Update shellescape requirement from <3.5,>=3.4.1 to >=3.4.1,<3.9

Updates the requirements on [shellescape](https://github.com/chrissimpkins/shellescape) to permit the latest version.
- [Release notes](https://github.com/chrissimpkins/shellescape/releases)
- [Commits](chrissimpkins/shellescape@v3.4.1...v3.8.1)

---
updated-dependencies:
- dependency-name: shellescape
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1,7 +1,7 @@
 requests>=2.4.3
 ruamel.yaml>=0.12.4,<=0.16.5
 rdflib>=4.2.2,<5.1
-shellescape>=3.4.1,<3.5
+shellescape>=3.4.1,<3.9
 schema-salad>=7.1.20210518142926,<8
 prov==1.5.1
 bagit==1.8.1

setup.py

@@ -110,7 +110,7 @@
         # https://github.com/ionrock/cachecontrol/issues/137
         "ruamel.yaml >= 0.12.4, <= 0.16.5",
         "rdflib >= 4.2.2, < 5.1.0",
-        "shellescape >= 3.4.1, < 3.5",
+        "shellescape >= 3.4.1, < 3.9",
         # 7.1.20210518142926 or later required due to
         # https://github.com/common-workflow-language/schema_salad/issues/385
         "schema-salad >= 7.1.20210518142926, < 8",