Fix flake8 warnings after falke 3.8 upgrade (#441)

Summary:
This fixes some errors that showed up in the CI lint check after a new flake8 release.
Pull Request resolved: #441

Reviewed By: sdaulton

Differential Revision: D21537119

Pulled By: Balandat

fbshipit-source-id: 3d826b7687b9d048a4f362ae962ad73a62e1d8f6

Author: Balandat

botorch/acquisition/analytic.py

@@ -77,7 +77,7 @@ def _get_posterior(self, X: Tensor) -> Posterior:
 
     def set_X_pending(self, X_pending: Optional[Tensor] = None) -> None:
         raise UnsupportedError(
-            f"Analytic acquisition functions do not account for X_pending yet."
+            "Analytic acquisition functions do not account for X_pending yet."
         )
 
 

scripts/update_versions_html.py

@@ -44,8 +44,8 @@ def prepend_url(a_tag, base_url, version):
 
         # nav
         nav_links = soup.find("nav").findAll("a")
-        for l in nav_links:
-            l.attrs["href"] = prepend_url(l, base_url, v)
+        for nl in nav_links:
+            nl.attrs["href"] = prepend_url(nl, base_url, v)
 
         # version link
         t = soup.find("h2", {"class": "headerTitleWithLogo"}).find_next("a")
@@ -55,8 +55,8 @@ def prepend_url(a_tag, base_url, version):
 
         # footer
         nav_links = soup.find("footer").findAll("a")
-        for l in nav_links:
-            l.attrs["href"] = prepend_url(l, base_url, v)
+        for nl in nav_links:
+            nl.attrs["href"] = prepend_url(nl, base_url, v)
 
         # output files
         with open(base_path + "/new-site/v/{}/versions.html".format(v), "w") as outfile: