Bump version to 1.4.0

Changes since 1.3.0:

$ git log --oneline --no-merges v1.3.0..HEAD
f506980 Upgrade soy to 2023-12-13
10f92e0 Add fuller template for gitiles pretty logging
9dd1a2e Reapply "Soy: bump version and use new "??" operator"
70d9a1b Migrate usages of `and`/`or` to `&&`/`||`.
1946930 Revert "Soy: bump version and use new "??" operator"
b49a952 Common.soy: make explictely nullable the css parameter
3cc3548 Soy: bump version and use new "??" operator
d62af25 Enable more errorprone patterns
484ec1a Update bazel to 6.3.2
1210230 [errorprone] Fix JavaUtilDate
cf746f0 Update JGit to dc27dbd2f
d8e7ffb [errorprone] Fix see InvalidInlineTag
e2e3c6a [errorprone] Fix BadImport
ba9eb87 [errorprone] Fix EscapedEntity
8516506 Improve tools/run_dev.sh to allow custom flags
0f85ecb [errorprone] Remove unnecessary parentheses
c156c96 [errorprone] Annotate method returning null as nullable
30ea267 [errorprone] Remove null check for value which cannot be null
4a11466 [errorprone] Suppress AnnotateFormatMethod
0cda867 [errorprone] Fix empty javadoc block tags
010d3c3 [errorprone] Use Guava Splitter to avoid String#split
d5ce821 [errorprone] Annotate method formatting string
a0d00c5 [errorprone] Add missing javadoc summary
97196ea Update java-prettify to 32fa081a797a

Change-Id: I4f9a80d1027ba98e99e913b58bf7536fba51ed5d
diff --git a/version.bzl b/version.bzl
index fef692b..eb86312 100644
--- a/version.bzl
+++ b/version.bzl
@@ -3,4 +3,4 @@
 # Used by :install and :deploy when talking to the destination repository.
 # Project uses semantic versioning described at:
 # https://semver.org