Upgrade the Gradle wrapper to 7.6.1, with enabling the Java toolchain

[hiroyuki-sato]

• Upgrade the Gradle wrapper to 7.6.1, with enabling the Java toolchain
• Use a modern dependency lock file.
• Update embulk-{core|junit4|deps|spi} to 0.10.49
• Update embulk-util-config to 0.3.3
• Update embulk-util-json to 0.2.1
• Update embulk-util-timestamp to 0.2.2
• Update gradle-embulk-plugins to 0.5.5
• Update embulk-formatter-csv: to 0.10.42
• Update embulk-input-file: to 0.10.42
• Update embulk-output-file: to 0.10.42
• Update embulk-parser-csv: to 0.10.42

Replacing lockfile using the following commands.

for i in embulk-output-* ; do ./gradlew ${i}:dependencies --write-locks ; done
fd embulkPluginRuntime.lockfile | xargs rm -f

[hiroyuki-sato]

@dmikurube, Could you take a look when you get a chance?

[hiroyuki-sato]

@dmikurube @hito4t I removed the Guava and unified the variable name. Could you recheck this PR when you get a chance?

[hiroyuki-sato]

Thank you for the comments! Fixed coding styles!

[hiroyuki-sato]

@dmikurube , @hito4t Thanks! Could you merge this commit? (I don't have permission). Do you think I should squash this PR?

[dmikurube]

I don't think squash is needed. Let me merge this as @hito4t has also approved. Thanks for working on it!

[hiroyuki-sato]

Thanks!